Do not expand the opencl pragma names. This is so you can also have a define named the samed as the pragma and they do not interfere (ie. cl_khr_fp64).

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@129549 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Parse/ParsePragma.cpp

@@ -387,7 +387,7 @@ void
 PragmaOpenCLExtensionHandler::HandlePragma(Preprocessor &PP, 
                                            PragmaIntroducerKind Introducer,
                                            Token &Tok) {
-  PP.Lex(Tok);
+  PP.LexUnexpandedToken(Tok);
   if (Tok.isNot(tok::identifier)) {
     PP.Diag(Tok.getLocation(), diag::warn_pragma_expected_identifier) <<
       "OPENCL";