Add support for GCC_WARN_ABOUT_INVALID_OFFSETOF_MACRO to xcode emulation.

test/mac/xcode-gcc/warn_about_invalid_offsetof_macro.cc

Index: test/mac/xcode-gcc/warn_about_invalid_offsetof_macro.cc
===================================================================
--- test/mac/xcode-gcc/warn_about_invalid_offsetof_macro.cc	(revision 0)
+++ test/mac/xcode-gcc/warn_about_invalid_offsetof_macro.cc	(revision 0)
@@ -0,0 +1,15 @@
+// Copyright (c) 2012 Google Inc. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#define offsetof(st, m) ((unsigned)((char*)&((st*)0)->m - (char*)0))
+
+struct MyStruct {
+  virtual void MyFunc() = 0;
+  int my_member;
+};
+
+int main() {
+  unsigned x = offsetof(MyStruct, my_member);
+  return x ? 0 : 1;
+}
Property changes on: test/mac/xcode-gcc/warn_about_invalid_offsetof_macro.cc
___________________________________________________________________
Added: svn:eol-style
   + LF