Refactoring of extension methods in source packages (#78620)

* Change namespace of OneOrMany and TemporaryArray to MS.CA.Collections

* Cleanup Enumerable and ImmutableArray extensions

* Update imports/usings

Author: tmat

src/Analyzers/CSharp/Analyzers/RemoveUnnecessaryNullableDirective/CSharpRemoveUnnecessaryNullableDirectiveDiagnosticAnalyzer.cs

@@ -7,6 +7,7 @@
 using System.Diagnostics.CodeAnalysis;
 using System.Threading;
 using Microsoft.CodeAnalysis.CodeStyle;
+using Microsoft.CodeAnalysis.Collections;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Analyzers.RemoveUnnecessaryNullableDirective;
 using Microsoft.CodeAnalysis.CSharp.Syntax;

src/Analyzers/CSharp/Analyzers/UseSimpleUsingStatement/UseSimpleUsingStatementDiagnosticAnalyzer.cs

@@ -4,6 +4,7 @@
 
 using System.Collections.Generic;
 using System.Collections.Immutable;
+using System.Linq;
 using System.Threading;
 using Microsoft.CodeAnalysis.CodeStyle;
 using Microsoft.CodeAnalysis.CSharp.CodeStyle;

src/Analyzers/CSharp/CodeFixes/UseCollectionExpression/CSharpUseCollectionExpressionForFluentCodeFixProvider.cs

@@ -9,6 +9,7 @@
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis.CodeFixes;
+using Microsoft.CodeAnalysis.Collections;
 using Microsoft.CodeAnalysis.CSharp.Formatting;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.Diagnostics;
@@ -25,8 +26,8 @@
 namespace Microsoft.CodeAnalysis.CSharp.UseCollectionExpression;
 
 using static CSharpCollectionExpressionRewriter;
-using static CSharpUseCollectionExpressionForFluentDiagnosticAnalyzer;
 using static CSharpSyntaxTokens;
+using static CSharpUseCollectionExpressionForFluentDiagnosticAnalyzer;
 using static SyntaxFactory;
 
 [ExportCodeFixProvider(LanguageNames.CSharp, Name = PredefinedCodeFixProviderNames.UseCollectionExpressionForFluent), Shared]

src/Analyzers/CSharp/CodeFixes/UseLocalFunction/CSharpUseLocalFunctionCodeFixProvider.cs

@@ -14,6 +14,7 @@
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis.CodeFixes;
 using Microsoft.CodeAnalysis.CodeGeneration;
+using Microsoft.CodeAnalysis.Collections;
 using Microsoft.CodeAnalysis.CSharp.CodeGeneration;
 using Microsoft.CodeAnalysis.CSharp.Extensions;
 using Microsoft.CodeAnalysis.CSharp.Syntax;

src/Analyzers/Core/Analyzers/UseCollectionInitializer/AbstractUseCollectionInitializerDiagnosticAnalyzer.cs

@@ -6,6 +6,7 @@
 using System.Linq;
 using System.Threading;
 using Microsoft.CodeAnalysis.CodeStyle;
+using Microsoft.CodeAnalysis.Collections;
 using Microsoft.CodeAnalysis.Diagnostics;
 using Microsoft.CodeAnalysis.LanguageService;
 using Microsoft.CodeAnalysis.Shared.CodeStyle;

src/Analyzers/Core/Analyzers/UseObjectInitializer/AbstractUseObjectInitializerDiagnosticAnalyzer.cs

@@ -5,6 +5,7 @@
 using System.Collections.Immutable;
 using System.Linq;
 using Microsoft.CodeAnalysis.CodeStyle;
+using Microsoft.CodeAnalysis.Collections;
 using Microsoft.CodeAnalysis.Diagnostics;
 using Microsoft.CodeAnalysis.LanguageService;
 using Microsoft.CodeAnalysis.Shared.Collections;

src/Analyzers/Core/CodeFixes/AddExplicitCast/AbstractAddExplicitCastCodeFixProvider.cs

@@ -8,6 +8,7 @@
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CodeActions;
+using Microsoft.CodeAnalysis.Collections;
 using Microsoft.CodeAnalysis.Editing;
 using Microsoft.CodeAnalysis.LanguageService;
 using Microsoft.CodeAnalysis.PooledObjects;

src/Analyzers/Core/CodeFixes/AddParameter/AbstractAddParameterCodeFixProvider.cs

@@ -11,6 +11,7 @@
 using Microsoft.CodeAnalysis.CodeActions;
 using Microsoft.CodeAnalysis.CodeFixes;
 using Microsoft.CodeAnalysis.CodeGeneration;
+using Microsoft.CodeAnalysis.Collections;
 using Microsoft.CodeAnalysis.LanguageService;
 using Microsoft.CodeAnalysis.PooledObjects;
 using Microsoft.CodeAnalysis.Shared.Collections;

src/Analyzers/Core/CodeFixes/AliasAmbiguousType/AbstractAliasAmbiguousTypeCodeFixProvider.cs

@@ -10,6 +10,7 @@
 using Microsoft.CodeAnalysis.AddImport;
 using Microsoft.CodeAnalysis.CodeActions;
 using Microsoft.CodeAnalysis.CodeFixes;
+using Microsoft.CodeAnalysis.Collections;
 using Microsoft.CodeAnalysis.Editing;
 using Microsoft.CodeAnalysis.LanguageService;
 using Microsoft.CodeAnalysis.PooledObjects;

src/Analyzers/Core/CodeFixes/ConflictMarkerResolution/AbstractConflictMarkerCodeFixProvider.cs

@@ -5,6 +5,7 @@
 using System;
 using System.Collections.Immutable;
 using System.Diagnostics;
+using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis.CodeActions;

src/Analyzers/Core/CodeFixes/ImplementInterface/ImplementInterfaceGenerator_Property.cs

@@ -5,6 +5,7 @@
 using System.Collections.Immutable;
 using System.Linq;
 using Microsoft.CodeAnalysis.CodeGeneration;
+using Microsoft.CodeAnalysis.Collections;
 using Microsoft.CodeAnalysis.Editing;
 using Microsoft.CodeAnalysis.ImplementType;
 using Microsoft.CodeAnalysis.LanguageService;

src/Analyzers/Core/CodeFixes/NamingStyle/NamingStyleCodeFixProvider.cs

@@ -12,6 +12,7 @@
 using System.Threading.Tasks;
 using System.Xml.Linq;
 using Microsoft.CodeAnalysis.CodeActions;
+using Microsoft.CodeAnalysis.Collections;
 using Microsoft.CodeAnalysis.Diagnostics;
 using Microsoft.CodeAnalysis.LanguageService;
 using Microsoft.CodeAnalysis.NamingStyles;

src/Analyzers/VisualBasic/Tests/AddRequiredParentheses/AddRequiredParenthesesTests.vb

@@ -2,12 +2,6 @@
 ' The .NET Foundation licenses this file to you under the MIT license.
 ' See the LICENSE file in the project root for more information.
 
-Imports Microsoft.CodeAnalysis.AddRequiredParentheses
-Imports Microsoft.CodeAnalysis.CodeFixes
-Imports Microsoft.CodeAnalysis.Diagnostics
-Imports Microsoft.CodeAnalysis.Editor.VisualBasic.UnitTests.Diagnostics
-Imports Microsoft.CodeAnalysis.VisualBasic.AddRequiredParentheses
-
 Imports VerifyVB = Microsoft.CodeAnalysis.Editor.UnitTests.CodeActions.VisualBasicCodeFixVerifier(Of Microsoft.CodeAnalysis.VisualBasic.AddRequiredParentheses.VisualBasicAddRequiredParenthesesForBinaryLikeExpressionDiagnosticAnalyzer, Microsoft.CodeAnalysis.AddRequiredParentheses.AddRequiredParenthesesCodeFixProvider)
 
 Namespace Microsoft.CodeAnalysis.Editor.VisualBasic.UnitTests.AddRequiredParentheses

src/Analyzers/VisualBasic/Tests/GenerateEnumMember/GenerateEnumMemberTests.vb

@@ -3,8 +3,8 @@
 ' See the LICENSE file in the project root for more information.
 
 Imports Microsoft.CodeAnalysis.CodeFixes
-Imports Microsoft.CodeAnalysis.VisualBasic.CodeFixes.GenerateEnumMember
 Imports Microsoft.CodeAnalysis.Diagnostics
+Imports Microsoft.CodeAnalysis.VisualBasic.CodeFixes.GenerateEnumMember
 
 Namespace Microsoft.CodeAnalysis.Editor.VisualBasic.UnitTests.Diagnostics.GenerateEnumMember
     <Trait(Traits.Feature, Traits.Features.CodeActionsGenerateEnumMember)>

src/Analyzers/VisualBasic/Tests/GenerateMethod/GenerateConversionTests.vb

@@ -3,8 +3,8 @@
 ' See the LICENSE file in the project root for more information.
 
 Imports Microsoft.CodeAnalysis.CodeFixes
-Imports Microsoft.CodeAnalysis.VisualBasic.CodeFixes.GenerateMethod
 Imports Microsoft.CodeAnalysis.Diagnostics
+Imports Microsoft.CodeAnalysis.VisualBasic.CodeFixes.GenerateMethod
 
 Namespace Microsoft.CodeAnalysis.Editor.VisualBasic.UnitTests.Diagnostics.GenerateMethod
     Partial Public NotInheritable Class GenerateMethodTests

src/Analyzers/VisualBasic/Tests/ImplementAbstractClass/ImplementAbstractClassTests.vb

@@ -2,12 +2,10 @@
 ' The .NET Foundation licenses this file to you under the MIT license.
 ' See the LICENSE file in the project root for more information.
 
-Imports Microsoft.CodeAnalysis.CodeActions
 Imports Microsoft.CodeAnalysis.CodeFixes
 Imports Microsoft.CodeAnalysis.Diagnostics
 Imports Microsoft.CodeAnalysis.Editor.VisualBasic.UnitTests.Diagnostics
 Imports Microsoft.CodeAnalysis.ImplementType
-Imports Microsoft.CodeAnalysis.SymbolSearch
 Imports Microsoft.CodeAnalysis.VisualBasic.ImplementAbstractClass
 
 Namespace Microsoft.CodeAnalysis.Editor.VisualBasic.UnitTests.ImplementAbstractClass

src/Analyzers/VisualBasic/Tests/ImplementAbstractClass/ImplementAbstractClassTests_FixAllTests.vb

@@ -2,8 +2,6 @@
 ' The .NET Foundation licenses this file to you under the MIT license.
 ' See the LICENSE file in the project root for more information.
 
-Imports Microsoft.CodeAnalysis.VisualBasic.ImplementAbstractClass
-
 Namespace Microsoft.CodeAnalysis.Editor.VisualBasic.UnitTests.ImplementAbstractClass
     Partial Public Class ImplementAbstractClassTests
 

src/Analyzers/VisualBasic/Tests/ImplementInterface/ImplementInterfaceTests.vb

@@ -2,12 +2,10 @@
 ' The .NET Foundation licenses this file to you under the MIT license.
 ' See the LICENSE file in the project root for more information.
 
-Imports Microsoft.CodeAnalysis.CodeActions
 Imports Microsoft.CodeAnalysis.CodeFixes
 Imports Microsoft.CodeAnalysis.Diagnostics
 Imports Microsoft.CodeAnalysis.Editor.VisualBasic.UnitTests.Diagnostics
 Imports Microsoft.CodeAnalysis.ImplementType
-Imports Microsoft.CodeAnalysis.SymbolSearch
 Imports Microsoft.CodeAnalysis.VisualBasic.ImplementInterface
 
 Namespace Microsoft.CodeAnalysis.Editor.VisualBasic.UnitTests.ImplementInterface

src/Analyzers/VisualBasic/Tests/Iterator/IteratorTests.vb

@@ -2,12 +2,7 @@
 ' The .NET Foundation licenses this file to you under the MIT license.
 ' See the LICENSE file in the project root for more information.
 
-Imports Microsoft.CodeAnalysis.CodeFixes
-Imports Microsoft.CodeAnalysis.Diagnostics
-Imports Microsoft.CodeAnalysis.Editor.VisualBasic.UnitTests.Diagnostics
 Imports Microsoft.CodeAnalysis.Testing
-Imports Microsoft.CodeAnalysis.VisualBasic.CodeFixes.Iterator
-
 Imports VerifyConvertToIterator = Microsoft.CodeAnalysis.Editor.UnitTests.CodeActions.VisualBasicCodeFixVerifier(Of Microsoft.CodeAnalysis.Testing.EmptyDiagnosticAnalyzer, Microsoft.CodeAnalysis.VisualBasic.CodeFixes.Iterator.VisualBasicConvertToIteratorCodeFixProvider)
 Imports VerifyConvertToYield = Microsoft.CodeAnalysis.Editor.UnitTests.CodeActions.VisualBasicCodeFixVerifier(Of Microsoft.CodeAnalysis.Testing.EmptyDiagnosticAnalyzer, Microsoft.CodeAnalysis.VisualBasic.CodeFixes.Iterator.VisualBasicChangeToYieldCodeFixProvider)
 

src/Analyzers/VisualBasic/Tests/NewLines/ConsecutiveStatementPlacement/ConsecutiveStatementPlacementTests.vb

@@ -3,7 +3,6 @@
 ' See the LICENSE file in the project root for more information.
 
 Imports Microsoft.CodeAnalysis.CodeStyle
-
 Imports VerifyVB = Microsoft.CodeAnalysis.Editor.UnitTests.CodeActions.VisualBasicCodeFixVerifier(Of
     Microsoft.CodeAnalysis.VisualBasic.NewLines.ConsecutiveStatementPlacement.VisualBasicConsecutiveStatementPlacementDiagnosticAnalyzer,
     Microsoft.CodeAnalysis.NewLines.ConsecutiveStatementPlacement.ConsecutiveStatementPlacementCodeFixProvider)

src/Analyzers/VisualBasic/Tests/QualifyMemberAccess/QualifyMemberAccessTests.vb

@@ -5,8 +5,8 @@
 Imports Microsoft.CodeAnalysis.CodeFixes
 Imports Microsoft.CodeAnalysis.CodeStyle
 Imports Microsoft.CodeAnalysis.Diagnostics
-Imports Microsoft.CodeAnalysis.Options
 Imports Microsoft.CodeAnalysis.Editor.VisualBasic.UnitTests.Diagnostics
+Imports Microsoft.CodeAnalysis.Options
 Imports Microsoft.CodeAnalysis.VisualBasic.QualifyMemberAccess
 
 Namespace Microsoft.CodeAnalysis.Editor.VisualBasic.UnitTests.QualifyMemberAccess

src/Analyzers/VisualBasic/Tests/RemoveUnnecessaryParentheses/RemoveUnnecessaryParenthesesTests.vb

@@ -4,7 +4,6 @@
 
 Imports Microsoft.CodeAnalysis.CodeFixes
 Imports Microsoft.CodeAnalysis.Diagnostics
-Imports Microsoft.CodeAnalysis.Editor.UnitTests.Workspaces
 Imports Microsoft.CodeAnalysis.Editor.VisualBasic.UnitTests.Diagnostics
 Imports Microsoft.CodeAnalysis.Text
 Imports Microsoft.CodeAnalysis.VisualBasic.RemoveUnnecessaryParentheses

src/Analyzers/VisualBasic/Tests/SimplifyLinqExpression/VisualBasicSimplifyLinqExpressionTests.vb

@@ -2,9 +2,6 @@
 ' The .NET Foundation licenses this file to you under the MIT license.
 ' See the LICENSE file in the project root for more information.
 
-Imports Microsoft.CodeAnalysis.Editor.UnitTests.CodeActions
-Imports Microsoft.CodeAnalysis.SimplifyLinqExpression
-
 Imports VerifyVB = Microsoft.CodeAnalysis.Editor.UnitTests.CodeActions.VisualBasicCodeFixVerifier(Of
     Microsoft.CodeAnalysis.VisualBasic.SimplifyLinqExpression.VisualBasicSimplifyLinqExpressionDiagnosticAnalyzer,
     Microsoft.CodeAnalysis.SimplifyLinqExpression.SimplifyLinqExpressionCodeFixProvider)

src/Analyzers/VisualBasic/Tests/UseCoalesceExpression/UseCoalesceExpressionForIfNullStatementCheckTests.vb

@@ -2,12 +2,6 @@
 ' The .NET Foundation licenses this file to you under the MIT license.
 ' See the LICENSE file in the project root for more information.
 
-Imports Microsoft.CodeAnalysis.CodeFixes
-Imports Microsoft.CodeAnalysis.Diagnostics
-Imports Microsoft.CodeAnalysis.Editor.VisualBasic.UnitTests.Diagnostics
-Imports Microsoft.CodeAnalysis.UseCoalesceExpression
-Imports Microsoft.CodeAnalysis.VisualBasic.UseCoalesceExpression
-
 Imports VerifyVB = Microsoft.CodeAnalysis.Editor.UnitTests.CodeActions.VisualBasicCodeFixVerifier(Of
     Microsoft.CodeAnalysis.VisualBasic.UseCoalesceExpression.VisualBasicUseCoalesceExpressionForIfNullStatementCheckDiagnosticAnalyzer,
     Microsoft.CodeAnalysis.VisualBasic.UseCoalesceExpression.VisualBasicUseCoalesceExpressionForIfNullStatementCheckCodeFixProvider)

src/Analyzers/VisualBasic/Tests/UseIsNullCheck/UseIsNullCheckForReferenceEqualsTests.vb

@@ -3,9 +3,9 @@
 ' See the LICENSE file in the project root for more information.
 
 Imports Microsoft.CodeAnalysis.CodeFixes
-Imports Microsoft.CodeAnalysis.VisualBasic.UseIsNullCheck
 Imports Microsoft.CodeAnalysis.Diagnostics
 Imports Microsoft.CodeAnalysis.Editor.VisualBasic.UnitTests.Diagnostics
+Imports Microsoft.CodeAnalysis.VisualBasic.UseIsNullCheck
 
 Namespace Microsoft.CodeAnalysis.Editor.VisualBasic.UnitTests.UseIsNullCheck
     <Trait(Traits.Feature, Traits.Features.CodeActionsUseIsNullCheck)>

src/Compilers/CSharp/Portable/Binder/Binder.ValueChecks.cs

@@ -7,6 +7,7 @@
 using System.Collections.Immutable;
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
+using System.Linq;
 using Microsoft.CodeAnalysis.CSharp.CodeGen;
 using Microsoft.CodeAnalysis.CSharp.Symbols;
 using Microsoft.CodeAnalysis.PooledObjects;

src/Compilers/CSharp/Portable/Binder/Binder_Constraints.cs

@@ -5,6 +5,7 @@
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Diagnostics;
+using System.Linq;
 using Microsoft.CodeAnalysis.CSharp.Symbols;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.PooledObjects;

src/Compilers/CSharp/Portable/Binder/Binder_Patterns.cs

@@ -6,6 +6,7 @@
 using System.Collections.Immutable;
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
+using System.Linq;
 using Microsoft.CodeAnalysis.CSharp.Symbols;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.PooledObjects;

src/Compilers/CSharp/Portable/Binder/DecisionDagBuilder.cs

@@ -9,10 +9,10 @@
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Text;
+using Microsoft.CodeAnalysis.Collections;
 using Microsoft.CodeAnalysis.CSharp.Symbols;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.PooledObjects;
-using Microsoft.CodeAnalysis.Shared.Collections;
 using Roslyn.Utilities;
 
 namespace Microsoft.CodeAnalysis.CSharp

src/Compilers/CSharp/Portable/Binder/DecisionDagBuilder_ListPatterns.cs

@@ -3,6 +3,7 @@
 // See the LICENSE file in the project root for more information.
 
 using System.Diagnostics;
+using System.Linq;
 using Microsoft.CodeAnalysis.CSharp.Symbols;
 using Microsoft.CodeAnalysis.PooledObjects;
 

src/Compilers/CSharp/Portable/Binder/InMethodBinder.cs

@@ -8,6 +8,7 @@
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Diagnostics;
+using System.Linq;
 using Microsoft.CodeAnalysis.CSharp.Symbols;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Roslyn.Utilities;

src/Compilers/CSharp/Portable/Binder/Semantics/Conversions/ConversionsBase.cs

@@ -7,11 +7,11 @@
 using System.Collections.Immutable;
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
+using System.Linq;
 using System.Threading;
 using Microsoft.CodeAnalysis.CSharp.Symbols;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.PooledObjects;
-using Roslyn.Utilities;
 
 namespace Microsoft.CodeAnalysis.CSharp
 {

src/Compilers/CSharp/Portable/Binder/Semantics/Operators/BinaryOperatorOverloadResolution.cs

@@ -8,9 +8,9 @@
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Diagnostics;
+using Microsoft.CodeAnalysis.Collections;
 using Microsoft.CodeAnalysis.CSharp.Symbols;
 using Microsoft.CodeAnalysis.PooledObjects;
-using Microsoft.CodeAnalysis.Shared.Collections;
 using Roslyn.Utilities;
 
 namespace Microsoft.CodeAnalysis.CSharp

src/Compilers/CSharp/Portable/Binder/Semantics/OverloadResolution/OverloadResolution.cs

@@ -10,9 +10,9 @@
 using System.Diagnostics;
 using System.Linq;
 using Microsoft.Cci;
+using Microsoft.CodeAnalysis.Collections;
 using Microsoft.CodeAnalysis.CSharp.Symbols;
 using Microsoft.CodeAnalysis.PooledObjects;
-using Microsoft.CodeAnalysis.Shared.Collections;
 using Microsoft.CodeAnalysis.Symbols;
 using Roslyn.Utilities;
 

src/Compilers/CSharp/Portable/Binder/SwitchExpressionBinder.cs

@@ -5,10 +5,10 @@
 using System.Collections.Immutable;
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
+using Microsoft.CodeAnalysis.Collections;
 using Microsoft.CodeAnalysis.CSharp.Symbols;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.PooledObjects;
-using Microsoft.CodeAnalysis.Shared.Collections;
 using Roslyn.Utilities;
 
 namespace Microsoft.CodeAnalysis.CSharp

src/Compilers/CSharp/Portable/BoundTree/BoundDecisionDag.cs

@@ -9,9 +9,9 @@
 using System.Collections.Immutable;
 using System.Diagnostics;
 using System.Linq;
+using Microsoft.CodeAnalysis.Collections;
 using Microsoft.CodeAnalysis.CSharp.Symbols;
 using Microsoft.CodeAnalysis.PooledObjects;
-using Microsoft.CodeAnalysis.Shared.Collections;
 using Roslyn.Utilities;
 
 namespace Microsoft.CodeAnalysis.CSharp

src/Compilers/CSharp/Portable/Compilation/CSharpDeterministicKeyBuilder.cs

@@ -3,8 +3,7 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
-using System.Collections.Generic;
-using System.Text;
+using System.Linq;
 using Roslyn.Utilities;
 
 namespace Microsoft.CodeAnalysis.CSharp

src/Compilers/CSharp/Portable/Compilation/CSharpSemanticModel.cs

@@ -10,6 +10,7 @@
 using System.Diagnostics;
 using System.Linq;
 using System.Threading;
+using Microsoft.CodeAnalysis.Collections;
 using Microsoft.CodeAnalysis.CSharp.Symbols;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.PooledObjects;

src/Compilers/CSharp/Portable/Compilation/MemberSemanticModel.cs

@@ -11,6 +11,7 @@
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Threading;
+using Microsoft.CodeAnalysis.Collections;
 using Microsoft.CodeAnalysis.CSharp.Symbols;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.Operations;

src/Compilers/CSharp/Portable/Compilation/SymbolInfoFactory.cs

@@ -8,6 +8,7 @@
 using System.Collections.Immutable;
 using System.Diagnostics;
 using System.Linq;
+using Microsoft.CodeAnalysis.Collections;
 using Microsoft.CodeAnalysis.CSharp.Symbols;
 using Microsoft.CodeAnalysis.PooledObjects;
 using Roslyn.Utilities;

src/Compilers/CSharp/Portable/Declarations/MergedTypeDeclaration.cs

@@ -8,6 +8,7 @@
 using System.Collections.Immutable;
 using System.Diagnostics;
 using System.Threading;
+using Microsoft.CodeAnalysis.Collections;
 using Microsoft.CodeAnalysis.CSharp.Symbols;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.PooledObjects;