We're making a copy of ieee754.(cc|h) in Chromium in
crrev.com/c/2582607. To ensure this copy stays in sync, we're adding a
watchlist for changes on the original ieee754.(cc|h).

Also, watch for changes in dependency of ieee754.(cc|h)
overflowing-math.h, and for changes in the licenses (LICENSE.fdlibm).

Bug: chromium:1145192
Change-Id: I5a967266c8b5c5c973afc48d9b453915f228a268
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2593649Reviewed-by: Hannes Payer <hpayer@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Caleb Raitto <caraitto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72015}