This bumps the required stack space gap when the bootstrapper kicks off
compilation of native scripts during genesis. The stack requirements are
now higher for simulators in no-snapshot mode with Ignition being used.

R=jochen@chromium.org
TEST=mjsunit/regress/regress-681984
BUG=v8:6066

Change-Id: I65df388d1b57c09db124ac9a85d380b4edb7d260
Reviewed-on: https://chromium-review.googlesource.com/451275
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43675}