arm64: Implement VarHandle intrinsics for byte array views.

Using benchmarks provided by
    https://android-review.googlesource.com/1420959
on blueline little cores with fixed frequency 1420800:
                             before after
GetByteArrayViewInt          27.093 0.024
SetByteArrayViewInt          28.067 0.024
GetByteArrayViewBigEndianInt 27.142 0.026
SetByteArrayViewBigEndianInt 28.040 0.025

Test: testrunner.py --target --64 --optimizing
Bug: 71781600
Change-Id: I604326675042bd63dce8ec15075714003ca9915d
7 files changed