[OPENMP] Add dependency to clang/clang-headers etc. for in-tree build of libomp.
Add additional dependency to clang/clang-headers/FileCheck to avoid possible troubles with in-tree build/test of libomp + allow parallel testing of libomp. Also includes bugfixes for tests + improvements to avoid possible race conditions.
Differential Revision: http://reviews.llvm.org/D14055

llvm-svn: 251797
diff --git a/openmp/runtime/test/api/omp_get_wtime.c b/openmp/runtime/test/api/omp_get_wtime.c
index c93c2a5..d91312b 100644
--- a/openmp/runtime/test/api/omp_get_wtime.c
+++ b/openmp/runtime/test/api/omp_get_wtime.c
@@ -9,7 +9,7 @@
   double start;
   double end;
   double measured_time;
-  double wait_time = 0.25; 
+  double wait_time = 1.0; 
   start = 0;
   end = 0;
   start = omp_get_wtime();