GitLab

Allow fuzzers to opt out of using AFL's forkserver. Also opt v8 fuzzers
out of using it.
v8 fuzzers start threads when LLVMFuzzerInitialize is called. This breaks
AFL's forkserver because one cannot fork after a thread has started.
This is a speculative fix for crbug.com/875199

Bug: 797798, 875199, 796680
Change-Id: I12e8408afaba9c9ca435d031e4263fcc2f80c67f
Reviewed-on: https://chromium-review.googlesource.com/1187835Reviewed-by: Max Moroz <mmoroz@chromium.org>
Commit-Queue: Jonathan Metzman <metzman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#585874}