Extract renaming from D19181

Summary: This needs to get in before anything is released concerning attribute. If the old name gets in the wild, then we are stuck with it forever. Putting it in its own diff should getting that part at least in fast.

Reviewers: Wallbraker, whitequark, joker.eph, echristo, rafael, jyknight

Subscribers: llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D20417

llvm-svn: 270452