JIT: Allow use of cbz/cbnz for conditional branch gen.

Optimize conditional branch generation when comparing
with zero for ARM JIT. When possible use cbz/cbnz
instead of cmp+beq/cmp+bne.

This improves performance for usecases involving
code execution in Dalvik.

Change-Id: I8f7c44c87eb73d4da00a48fd86220a62cb0515f5
Signed-off-by: Patrik Ryd <patrik.ryd@stericsson.com>
Now that abort(3) is fixed, dvmAbort can be simplified.

The fix to abort(3) has SHA 7e6ce1a3c52d8533fed92c143419fedb0c93988a.
(https://android-review.googlesource.com/#/c/60341/)

Change-Id: I89e7ed174cbd08ad9046a98e2fdd73af8ae3ee5c
Merge "Now that abort(3) is fixed, dvmAbort can be simplified."
Merge "JIT: Allow use of cbz/cbnz for conditional branch gen."
Merge https://android.googlesource.com/platform/dalvik into jb-devel