Function shift_simd_by_simd 

fn shift_simd_by_simd<'tcx>(
    ecx: &mut MiriInterpCx<'tcx>,
    left: &OpTy<'tcx>,
    right: &OpTy<'tcx>,
    which: ShiftOp,
    dest: &MPlaceTy<'tcx>,
) -> InterpResult<'tcx, ()>