To avoid running infinitely or hitting the stack size limit, bound the
number of steps to execute in the interpreter to 16k.

R=ahaas@chromium.org
BUG=chromium:708457

Change-Id: Ib101bbbc06627641dae2fd1cd1a8d950aa504eaf
Reviewed-on: https://chromium-review.googlesource.com/469609
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44446}