Code from ARES-6 Basic:

  ldur w11, [x5, #15]
  asr w11, w11, #1
  sxtw x11, w11

With this CL:

  ldur w11, [x5, #15]
  sbfx x11, x11, #1, #31

This increases performance of Ares6 Basic by ~2% on Cortex-A53.
Also reduces the snapshot by ~2000 instructions.

Change-Id: Ie9801da730f832337306422d2a9c63461d9e5690
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1849530Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Martyn Capewell <martyn.capewell@arm.com>
Cr-Commit-Position: refs/heads/master@{#64235}