am e3912c91: am 31c9763a: merge in KQS81M

* commit 'e3912c91273e31a79de9393a6efa9e2abbb74fd8':
  Make inlined CAS32 loop until store is successful if values match.
  Revert "Fix CAS intrinsic to clear exclusive if values don't match."
  Fix ImageHeader.IsValid
  Add flock(2)ing on dex-cache files to prevent races