Finish AArch64 encoder/decoder

Created by: egrimley

https://github.com/DynamoRIO/dynamorio/wiki/AArch64-Port: "At the end of 2016, DynamoRIO's encoder/decoder handles all the load/store instructions, including load/store of FP/SIMD registers, and all the instructions that do not operate on FP/SIMD registers, up to ARMv8.2."

The non-load/store FP/SIMD instructions should be added.

See #1569, #2440 and #2443.