Revert "Remove harmful attempts to be helpful in pthread_mutex functions."

This reverts commit 53f15d0325feeaf7e58dc79fce4ddf55e0a64b7a.
Revert "ARM: Change dmb domain for bionic_atomic_barrier()"

This reverts commit 59306820664c85de2a1e42b35f72b79ce9e3c196.