ARM/ARM64: Clean up Baker RB introspection codegen.

Remove the guard flags and remove unused code.

Avoid unnecessary temporaries for JIT. This was missed in
    https://android-review.googlesource.com/725705

Test: m test-art-host-gtest
Test: Pixel 2 XL boots.
Test: m test-art-target-gtest
Test: testrunner.py --target --optimizing --jit
Bug: 36141117
Change-Id: Ic1bdc640db3f18d7169b0e62644f190e65a98d38
4 files changed