Integrate the following from the 'objective-rewrite' branch:

http://llvm.org/viewvc/llvm-project?view=rev&revision=71086

Note - This commit only includes the fix for:

<rdar://problem/6309338> slightly different error message format for Visual Studio.

The fix for <rdar://problem/6845623> from protocol to template. is separate/forthcoming.

llvm-svn: 90642