on cxx-abi-dev (thread starting 2016-10-11). This is currently hidden behind a
cc1-only -m flag, pending discussion of how best to deal with language changes
that require use of new symbols from the ABI library.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@285664 91177308-0d34-0410-b5e6-96231b3b80d8