Add __builtin_va_list definitions for x86_64 and ppc64.

llvm-svn: 42943
diff --git a/clang/Basic/TargetInfo.cpp b/clang/Basic/TargetInfo.cpp
index 20f12c7..a3e0a21 100644
--- a/clang/Basic/TargetInfo.cpp
+++ b/clang/Basic/TargetInfo.cpp
@@ -260,4 +260,9 @@
   }
 }
 
+/// getVAListDeclaration - Return the declaration to use for
+/// __builtin_va_list, which is target-specific.
+const char *TargetInfo::getVAListDeclaration() const {
+  return PrimaryTarget->getVAListDeclaration();
+}