[clang][Parser] Fix lookup of builtins with pragma intrinsic

Signed-off-by: Sarnie, Nick <[email protected]>

Author: sarnex

clang/lib/Parse/ParsePragma.cpp

@@ -3800,7 +3800,7 @@ void PragmaMSIntrinsicHandler::HandlePragma(Preprocessor &PP,
     // If the builtin hasn't already been declared, declare it now.
     DeclarationNameInfo NameInfo(II, Tok.getLocation());
     LookupResult Previous(Actions, NameInfo, Sema::LookupOrdinaryName,
-                          Actions.forRedeclarationInCurContext());
+                          RedeclarationKind::NotForRedeclaration);
     Actions.LookupName(Previous, Actions.getCurScope(),
                        /*CreateBuiltins*/ false);
     if (Previous.empty())

clang/test/Sema/builtin-pragma-intrinsic-namespace.cpp

@@ -0,0 +1,14 @@
+// RUN: %clang_cc1 -triple x86_64-windows-msvc -fms-compatibility -fsyntax-only -verify %s
+
+// expected-no-diagnostics
+
+unsigned __int64 _umul128(unsigned __int64, unsigned __int64,
+                          unsigned __int64 *);
+
+namespace {}
+#pragma intrinsic(_umul128)
+
+ void foo() {
+   unsigned __int64 carry;
+   unsigned __int64 low = _umul128(0, 0, &carry);
+ }