[OPENMP50]Add parsing/sema analysis for nontemporal clause.

Add basic support for parsing/sema analysis of the nontemporal clause in
simd-based directives.
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index a8ea856..a632072 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -10,6 +10,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "clang/AST/OpenMPClause.h"
 #include "clang/Serialization/ASTRecordWriter.h"
 #include "ASTCommon.h"
 #include "ASTReaderInternals.h"
@@ -6537,3 +6538,10 @@
   Record.AddSourceLocation(C->getLParenLoc());
   Record.AddSourceLocation(C->getAtomicDefaultMemOrderKindKwLoc());
 }
+
+void OMPClauseWriter::VisitOMPNontemporalClause(OMPNontemporalClause *C) {
+  Record.push_back(C->varlist_size());
+  Record.AddSourceLocation(C->getLParenLoc());
+  for (auto *VE : C->varlists())
+    Record.AddStmt(VE);
+}