9549f7560f
Restore a reverted commit, with the silly mistake fixed. Sorry for the previous breakage. Be consistent about how we treat atomics in non-zero address spaces. If we get to the backend, we tend to lower them as if in address space 0. Do the same if we need to insert a libcall instead. Differential Revision: https://reviews.llvm.org/D58760 llvm-svn: 355540