Clean up bin offset assignment in ImageWriter.

And add padding for tail region of multi-region objects.
(Fill it with objects for now as we're not copying the
app image to normal heap regions.)

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Test: aosp_taimen-userdebug boots.
Test: run-gtests.sh
Test: testrunner.py --target --optimizing
Bug: 26687569
Change-Id: I7134540fc3fdd78f37c8d04b3eca5e2ae553dd30
2 files changed