Revert "Revert "Scan immune spaces using mod union tables.""

This reverts commit ccf7c8a68972f3b7bfa38af0c6b792f712f83765.

Change-Id: Iee618d9ae78e1dcdea4a7ecbe9253821d4d4d015
Test: N9 boot, art tests, Ritz EAAC.
Bug: 29516968
Bug: 29517059
Bug: 12687968
1 file changed