Improvements in Jit compare UI
x86 jit: A tiny optimization and a tiny bugfix
x86 jit: For clarity, use TEMPREG where it doesn't matter that it's EAX.

Might have missed a few places.
x86 jit: Use LEA to emulate addu but only when it can save a few bytes
x86: Minor soft-skinning optimization
x86 jit: Fix+enable quaternion product, optimize "sw zero, *"
ARM Jit: Implement quaternion multiplication