Try to eliminate GCC_CAST hack in a manner that should work for both

GCC and MSVC.

llvm-svn: 160397

clang/include/clang/AST/RecursiveASTVisitor.h

@@ -464,19 +464,11 @@ template<typename Derived>
 bool RecursiveASTVisitor<Derived>::dataTraverseNode(Stmt *S,
                                                     bool &EnqueueChildren) {
 
-// The cast for DISPATCH_WALK is needed for older versions of g++, but causes
-// problems for MSVC.  So we'll skip the cast entirely for MSVC.
-#if defined(_MSC_VER)
-  #define GCC_CAST(CLASS)
-#else
-  #define GCC_CAST(CLASS) (bool (RecursiveASTVisitor::*)(CLASS*))
-#endif
-
   // Dispatch to the corresponding WalkUpFrom* function only if the derived
   // class didn't override Traverse* (and thus the traversal is trivial).
 #define DISPATCH_WALK(NAME, CLASS, VAR) \
-  if (&RecursiveASTVisitor::Traverse##NAME == \
-      GCC_CAST(CLASS)&Derived::Traverse##NAME) \
+  if ((bool (Derived::*)(CLASS*))&RecursiveASTVisitor::Traverse##NAME == \
+      &Derived::Traverse##NAME) \
     return getDerived().WalkUpFrom##NAME(static_cast<CLASS*>(VAR)); \
   EnqueueChildren = false; \
   return getDerived().Traverse##NAME(static_cast<CLASS*>(VAR));
@@ -516,7 +508,6 @@ bool RecursiveASTVisitor<Derived>::dataTraverseNode(Stmt *S,
   }
 
 #undef DISPATCH_WALK
-#undef GCC_CAST
 
   return true;
 }