VertexDecoder JIT: Add the last missing ones except morph, I think.
ARM optimization in ADDI2R: Dual adds instead of MOVI2R, ADD when possible
Minor optimization in IndexGenerator::AddStrip.
Add an optimization to discard registers at the end of functions when possible.

Works in some games but crashes many so hiding it for now. Do not add UI.
ARMjit: Optimize mfc1, mtc1
ARMjit: Optimize mfv, mtv