D9306 omp 4.1 async offload support (partial): build changes for version 4.1

llvm-svn: 236746
diff --git a/openmp/runtime/cmake/PerlFlags.cmake b/openmp/runtime/cmake/PerlFlags.cmake
index c34d29d..978b72f 100644
--- a/openmp/runtime/cmake/PerlFlags.cmake
+++ b/openmp/runtime/cmake/PerlFlags.cmake
@@ -71,6 +71,9 @@
     elseif(${STUBS_LIBRARY})
         append_gd_flags("-D stub")
     endif()
+    if(${omp_version} GREATER 41 OR ${omp_version} EQUAL 41)
+        append_gd_flags("-D OMP_41")
+    endif()
     if(${omp_version} GREATER 40 OR ${omp_version} EQUAL 40)
         append_gd_flags("-D OMP_40")
     endif()