Clean up interface check cast

Changed arm, arm64 to use less labels and removed forward branch
in the success case.

Cleaned up X86, X86_64 to remove the is_null label.

Bug: 12687968
Bug: 32577579

Test: test-art-host, test-art-target CC
Change-Id: Iba426dff548b2ef42198fad13efeb075f7c724a7
4 files changed