vectorized VMACU
vectorized VMACU

vmacu_old.asm function has 99 instructions.

vmacu_new.asm function has 50 instructions.

mupen64plus/mupen64plus-rsp-cxd4,mupen64plus/mupen64plus-rsp-cxd4,mupen64plus/mupen64plus-rsp-cxd4