RazorPreCompilation.cs error on dnx core 5.0

[danroth27]

From dotnet/aspnetcore#533 by @dopare
Created started web application for beta4. Removed dnx451 from frameworks and got compilation error.

RazorPreCompilation.cs(5,17,5,23): DNX Core 5.0 error CS0234: The type or namespace name 'AspNet' does not exist in the namespace 'Microsoft' (are you missing an assembly reference?)

[troydai]

It only reproduces on beta4.

[troydai]

On another look. This issue actually repos on beta5. The difference is we swallow the build exception. I'm investigating the source.

[troydai]

The root cause of this issue is because the created load context for preprocess module contains a library manager of runtime target framework instead of application target framework. https://github.com/aspnet/dnx/blob/dev/src/Microsoft.Framework.Runtime.Roslyn/RoslynCompiler.cs#L234

[davidfowl]

@troydai this bug is fixed right?