The hight 32 bits of the result of MULHW/MULHWU are undefined
which could be set to any random bits. This CL adds a few
bits to the hight 32 bits of the result to simulate this behaviour.

Change-Id: Iaaaaf83f39e2f4c051071ebd68023dc5fd024595
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2378573Reviewed-by: Junliang Yan <jyan@ca.ibm.com>
Commit-Queue: Milad Farazmand <miladfar@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#69578}