This also introduces two new simplified operators,
NumberIsFinite and ObjectIsFiniteNumber; the latter
handles all values, and the former is a fast-path
of the fast-path that is inserted by typed optimization
if we know the input has Type::Number.

Bug: v8:7340, v8:7250
Change-Id: I1b4812c01bf470bbff40fb3da6e11da543a22cd2
Reviewed-on: https://chromium-review.googlesource.com/951244
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51980}