vex kreg ops: fix VL test and emit modrm.mod value
vex kreg ops: fix VL test and emit modrm.mod value

Change-Id: I2ef471cb9fdecae61382c30f3312ea2515d847aa
(cherry picked from commit bd2e613f51db74fdeb3c2f5edddad01942255e94)

intelxed/xed,intelxed/xed,intelxed/xed,intelxed/xed