This is likely the major change of the series, as Call nodes are the
focus of call reducer (and to a lesser extent other phases like
inlining).

This CL essentially adds the new input to Call nodes, and updates the
rest of the pipeline. As a (fairly large) drive-by, I also introduce
the JSCallNode wrapper class and apply it in call reducer.

This change, although large, will hopefully make future refactorings
*much* easier, since it is now clear where certain assumptions about
Call node layout are made.

Bug: v8:8888
Change-Id: Ia15fe0ba459b6034863a5815a4e4662cee41fc83
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2264353
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68616}