port 588e15c0 (r37345)

  original commit message:
  The opcodes for 'cmpw r/m16, r16' and 'cmpw r16, r/m16' were swapped, causing a few issues when less than/greater than comparison were performed.

  Adds a regression test.

BUG=

Review-Url: https://codereview.chromium.org/2119793002
Cr-Commit-Position: refs/heads/master@{#37469}