Fix a mutator lock violation in the generic JNI end sequence.

artQuickGenericJniEndTrampoline() was accessing objects without a shared
mutator lock right after returning from a JNI call but before switching
to the runnable state.

This fixes crashes with table lookup read barriers enabled.

Bug: 12687968
Change-Id: I94ad9ca276750f58cb68b2fa9eb8cdeb371f021b
2 files changed