Merge changes I9aff8b78,I75c2f919 am: fb911ef
am: 7d75aa8

* commit '7d75aa87d6e06f7268765843ae943da0beef0271':
  Enable builds with Clang.
  Switch to a volatile store to a NULL pointer.

Change-Id: I46db2977315e812331f347344eae83b1041978d2