This is to enable it to also be used for reporting AsmJS errors such that
this can be moved off-thread.

BUG=v8:5203

Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: Ia46040b14d010702f10c02b8254aea84cba4d54d
Reviewed-on: https://chromium-review.googlesource.com/735606
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48881}