[clang] Add abi-breaking-checks support to clang

Summary: You can now use REQUIRES:abi-breaking-checks in clang too

Reviewers: chapuni, probinson, ddunbar, jroelofs

Reviewed By: jroelofs

Subscribers: jroelofs, cfe-commits

Differential Revision: https://reviews.llvm.org/D35426

llvm-svn: 309049