ART: Add lock and unlock stubs for ARM64, fix for X86-64

Basic translation of ARM stubs using dmb memory barrier.

Fix placement of dmb in unlock_object of ARM and ARM64.

Update lock and unlock tests in stub_test to force fat locks.

Fix X86-64 unlock stub.

Change-Id: Ie2e4328d9631e06843115888644e75fde8b319ee
4 files changed