Fix implementation of volatile stores

Volatile stores are synchronization actions, not merely releasing
stores, so an additional barrier is required.  We also have the
option of using atomic operations, but that's not recommended (except
for 64-bit fields, where we don't have a choice).

Bug 3338450

Change-Id: Ibfa3486eb89af7769c81bcf892b3fee50d2028d4
1 file changed