This uses the common macro lists instead of duplicating the list of
available math functions and values in {AsmJs::IsStdlibValid}.

R=rossberg@chromium.org
BUG=v8:6127

Change-Id: Ic480d74bb0b5f0f425d1e601e5128fa6f466bea1
Reviewed-on: https://chromium-review.googlesource.com/481260Reviewed-by: Andreas Rossberg <rossberg@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44725}