arch-arm: Implement ARMv8.3-JSConv

This commit implements Armv8 javascript float point convertion instructions
VJVCT and FJCVTZS.

Change-Id: I1b24839daef775bbb1eb9da5f32c4bb3843e0b28
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/25023
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
6 files changed