Add a watchlist for ieee754.(cc|h) changes.

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/+/2593649
Reviewed-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}

WATCHLISTS

@@ -87,6 +87,11 @@
     'tracing': {
       'filepath': 'src/tracing/',
     },
+    'ieee754': {
+      'filepath': 'src/base/ieee754\.(cc|h)' \
+                  '|src/base/overflowing-math.h' \
+                  '|LICENSE.fdlibm',
+    }
   },
 
   'WATCHLISTS': {
@@ -133,5 +138,9 @@
       'lpy+v8tracing@chromium.org',
       'fmeawad@chromium.org',
     ],
+    'ieee754': [
+      'rtoy+watch@chromium.org',
+      'hongchan+watch@chromium.org'
+    ],
   },
 }