For each single bug, the fuzzer might find many very similar inputs
which trigger this bug. All of them are reported as individual bugs
currently, which means lots of noise in bug reports and increased
workload for the clusterfuzz sheriffs.
After this change, all bugs of the same category ("compiles !=
validates", "interpreter != liftoff", ...) will be grouped together.
This requires us to fix them soon after reporting, as they will hide
all other bugs of the same category.

R=ahaas@chromium.org
CC=mmoroz@chromium.org

Change-Id: Ie203eed0c7681e3450df977b10c0d9dbbc402d34
Reviewed-on: https://chromium-review.googlesource.com/758438Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49231}