When shiftAmt is 0 for a UQRSHL instruction, the code called bits() with incorrect arguments. This fixes a left-shift of 0 to be a NOP/mov, as required. Change-Id: Ic86ca40ac42bfb767a09e8c65a53cec56382a008 Co-authored-by: Marton Erdos <marton.erdos@arm.com>