Previously these were called (real) stack limit on one end, (real)
jslimit on the other. With this CL we consistently use jslimit
everywhere.

Tbr: tebbi@chromium.org
Bug: v8:9534
Change-Id: I9f86ac113bb9682544c365d54f666c1312a073a6
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1748738
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63179}