[OPENMP 4.5] parsing/sema support for 'nogroup' clause.
OpenMP 4.5 adds 'taskloop' and 'taskloop simd' directives. These directives have new 'nogroup' clause. Patch adds basic parsing/sema support for this clause.

llvm-svn: 254899
diff --git a/clang/test/OpenMP/taskloop_misc_messages.c b/clang/test/OpenMP/taskloop_misc_messages.c
index 23d337a..f9e084e 100644
--- a/clang/test/OpenMP/taskloop_misc_messages.c
+++ b/clang/test/OpenMP/taskloop_misc_messages.c
@@ -52,6 +52,10 @@
 #pragma omp taskloop foo bar
   for (i = 0; i < 16; ++i)
     ;
+// expected-error@+1 {{directive '#pragma omp taskloop' cannot contain more than one 'nogroup' clause}}
+#pragma omp taskloop nogroup nogroup
+  for (i = 0; i < 16; ++i)
+    ;
 }
 
 void test_non_identifiers() {