[OPENMP] -fopenmp enables OpenMP support (fix for http://llvm.org/PR23492)

-fopenmp turns on OpenMP support and links libiomp5 as OpenMP library. Also there is -fopenmp={libiomp5|libgomp} option that allows to override effect of -fopenmp and link libgomp library (if -fopenmp=libgomp is specified).
Differential Revision: http://reviews.llvm.org/D9736

llvm-svn: 237769
diff --git a/clang/test/OpenMP/parallel_sections_reduction_messages.cpp b/clang/test/OpenMP/parallel_sections_reduction_messages.cpp
index d152f49..2ed828d 100644
--- a/clang/test/OpenMP/parallel_sections_reduction_messages.cpp
+++ b/clang/test/OpenMP/parallel_sections_reduction_messages.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -verify -fopenmp=libiomp5 -ferror-limit 100 -o - %s
+// RUN: %clang_cc1 -verify -fopenmp -ferror-limit 100 -o - %s
 
 void foo() {
 }