[flang][cuda] Remove restriction on device subprogram (llvm#89677)

Newer version allow `pure`, `elemental` and `recursive` on device
subprogram.

Author: clementval

flang/lib/Semantics/check-declarations.cpp

@@ -1436,10 +1436,6 @@ void CheckHelper::CheckSubprogram(
   }
   if (cudaAttrs && *cudaAttrs != common::CUDASubprogramAttrs::Host) {
     // CUDA device subprogram checks
-    if (symbol.attrs().HasAny({Attr::RECURSIVE, Attr::PURE, Attr::ELEMENTAL})) {
-      messages_.Say(symbol.name(),
-          "A device subprogram may not be RECURSIVE, PURE, or ELEMENTAL"_err_en_US);
-    }
     if (ClassifyProcedure(symbol) == ProcedureDefinitionClass::Internal) {
       messages_.Say(symbol.name(),
           "A device subprogram may not be an internal subprogram"_err_en_US);

flang/test/Semantics/cuf02.cuf

@@ -5,14 +5,11 @@ module m
     end
   end interface
  contains
-  !ERROR: A device subprogram may not be RECURSIVE, PURE, or ELEMENTAL
-  recursive attributes(device) subroutine s1
+  recursive attributes(device) subroutine s1 ! ok
   end
-  !ERROR: A device subprogram may not be RECURSIVE, PURE, or ELEMENTAL
-  pure attributes(device) subroutine s2
+  pure attributes(device) subroutine s2 ! ok
   end
-  !ERROR: A device subprogram may not be RECURSIVE, PURE, or ELEMENTAL
-  elemental attributes(device) subroutine s3
+  elemental attributes(device) subroutine s3 ! ok
   end
   subroutine s4
    contains
@@ -32,14 +29,11 @@ module m
   !ERROR: A function may not have ATTRIBUTES(GLOBAL) or ATTRIBUTES(GRID_GLOBAL)
   attributes(global) real function f1
   end
-  !ERROR: A device subprogram may not be RECURSIVE, PURE, or ELEMENTAL
-  recursive attributes(global) subroutine s7
+  recursive attributes(global) subroutine s7 ! ok
   end
-  !ERROR: A device subprogram may not be RECURSIVE, PURE, or ELEMENTAL
-  pure attributes(global) subroutine s8
+  pure attributes(global) subroutine s8 ! ok
   end
-  !ERROR: A device subprogram may not be RECURSIVE, PURE, or ELEMENTAL
-  elemental attributes(global) subroutine s9
+  elemental attributes(global) subroutine s9 ! ok
   end
 end