Fix a race condition in RosAlloc.

Fix a race condition in RosAlloc between RosAlloc::BulkFree() and
RosAlloc::RevokeThreadLocalRuns() with regard to bulk_free_bit_map.

(Cherry-pick commit 70f60042558e0a766e98f2aaefbf80596ace4d53)

Bug: 13192845
Bug: 12592026
Change-Id: I21afe8f9f3ad4166762d2bbfa0a6ae9484d8b12b
2 files changed