ARM64: Move from FPRegister to VRegister based API

VIXL has had FPRegister as an alias for VRegister for backward
compatibility. In the latest upstream VIXL the alias has been removed and all
FPRegister based API has became VRegister based. As AOSP VIXL is being
updated to the latest upstream VIXL all uses of FPRegister based API
must be replaced with VRegister based API.
This CL moves ART from FPRegister based API to VRegister based API.

Test: test.py --host --optimizing --jit --gtest
Test: test.py --target --optimizing --jit
Test: run-gtests.sh
Change-Id: I12541c16d0557835ea19c8667ae18c6601359b05
6 files changed