In the trap handler we validate the list of registered code objects
every time we register or de-register a new code object. The complexity
of this validation is O(num-code-objects * num-instructions). For big
WebAssembly modules with several hundred thousand code objects, this
validation causes significant overhead (we saw up to 10x) and makes
debugging very tedious. With this CL I mark the validation as slow.
Thereby it is still enabled in most tests on our bots, but it is
possible to disable validation when debugging large web applications.

The referenced bug issue was created by developers who had problems
with debugging because of this issue.

R=mark@chromium.org

Bug: v8:8536
Change-Id: If7ecb554eebcb04eb43a1f791b96c7a42a47e60f
Reviewed-on: https://chromium-review.googlesource.com/c/1442634Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59181}