Avoid read barriers for inlined check cast

Avoiding read barriers improves speed and reduces code size.

Doing this can never result in false positives, only false negatives.
These false negatives are handled correcly by rechecking in the
entrypoint.

Ritzperf code size for CC:
arm32: 13439400->13300136 (-1.04%)
arm64: 16405120->16253568 (-0.92%)

Perf: TODO

Bug: 29516974
Bug: 12687968

Test: test-art-host, run ritzperf both with CC

Change-Id: Ie024e0b1e8ee415781fb73e8029e87e8a5318f86