The x87 port itself has been gone for awhile.

Bug: v8:7310
Change-Id: I1c938ba93720af361733f2c09dc5f128173b5675
Reviewed-on: https://chromium-review.googlesource.com/935198Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51581}