[OPENMP 4.5] parsing/sema support for 'grainsize' clause.
OpenMP 4.5 adds 'taksloop' and 'taskloop simd' directives, which have 'grainsize' clause. Patch adds parsing/sema analysis of this clause.

llvm-svn: 254903
diff --git a/clang/lib/Basic/OpenMPKinds.cpp b/clang/lib/Basic/OpenMPKinds.cpp
index 4a9e7fd..4c4d151 100644
--- a/clang/lib/Basic/OpenMPKinds.cpp
+++ b/clang/lib/Basic/OpenMPKinds.cpp
@@ -138,6 +138,7 @@
   case OMPC_num_teams:
   case OMPC_thread_limit:
   case OMPC_priority:
+  case OMPC_grainsize:
   case OMPC_nogroup:
     break;
   }
@@ -240,6 +241,7 @@
   case OMPC_num_teams:
   case OMPC_thread_limit:
   case OMPC_priority:
+  case OMPC_grainsize:
   case OMPC_nogroup:
     break;
   }