Use sizeof() instead of hard-coding a size for WrittenBuiltinSpecs, eek!

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@94024 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/AST/TypeLoc.h

@@ -410,7 +410,7 @@ public:
   }
 
   unsigned getExtraLocalDataSize() const {
-    return needsExtraLocalData() ? 4 : 0;
+    return needsExtraLocalData() ? sizeof(WrittenBuiltinSpecs) : 0;
   }
 
   SourceRange getSourceRange() const {