[MS] Re-add support for the ARM interlocked bittest intrinscs

Adds support for these intrinsics, which are ARM and ARM64 only:
  _interlockedbittestandreset_acq
  _interlockedbittestandreset_rel
  _interlockedbittestandreset_nf
  _interlockedbittestandset_acq
  _interlockedbittestandset_rel
  _interlockedbittestandset_nf

Refactor the bittest intrinsic handling to decompose each intrinsic into
its action, its width, and its atomicity.

llvm-svn: 334239