port 1da4b88e (r34978)

  original commit message:
  The idiv instruction has 2 registers as output. This needs to be
  modeled so that the move optimizer won't incorrectly elide away
  moves.

BUG=

Review URL: https://codereview.chromium.org/1823403002

Cr-Commit-Position: refs/heads/master@{#35018}