Partial fix for <rdar://problem/6645157> [clang on Xcode; regression]: error:...

Partial fix for <rdar://problem/6645157> [clang on Xcode; regression]: error: instance variable 'someField' is private.

A recent regression caused by http://llvm.org/viewvc/llvm-project?rev=65912&view=rev.

This commit isn't fully baked. Nevertheless, it should cause Xcode to compile again. Will speak with Fariborz offline.

llvm-svn: 66045