ARM64: More JIT Code Cache maintenace

Move implementation closer to ARM's sample code.

Bug: 62356545
Test: art/test.py --target
Change-Id: Ic205c700528f45afc281fb20e9336c9737d5f409
(cherry picked from commit 17272ab679c9b5f5dac8754ac070b78b15271c27)
1 file changed