The bugs are all due to the asm switch:
https://chromium-review.googlesource.com/c/583655/

The default case switched on --validate-asm, so we now compare:
--validate-asm
with
--validate-asm --stress-validate-asm --suppress-asm-messages

@mstarzinger: Should also the default pass --suppress-asm-messages?

If we want to maintain comparing those two variants, then adding "--suppress-asm-messages" would do the trick. But then we would need to add "--suppress-asm-messages" to _all_ variants, otherwise the other variant combinations will start to fail.

The following revision refers to this bug:
  https://chromium.googlesource.com/v8/v8.git/+/0cda6ffed7de59b3a94d15ae36062df398cdf0c4

commit 0cda6ffed7de59b3a94d15ae36062df398cdf0c4
Author: Michael Achenbach <machenbach@chromium.org>
Date: Wed Jul 26 11:51:44 2017

[foozzie] Suppress asm messages in all comparison configurations

TBR=mstarzinger@chromium.org
NOTRY=true

Bug:  chromium:748981 
Change-Id: I2043d283bd4eb6d98082f202d88638b3ca96a7c8
Reviewed-on: https://chromium-review.googlesource.com/586687
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46897}
[modify] https://crrev.com/0cda6ffed7de59b3a94d15ae36062df398cdf0c4/tools/foozzie/v8_foozzie.py

The above commit will suppress all the bugs. We can wait out the problem. Tomorrow, the fixed testing will close all the bugs again...

All bugs got auto-closed again. We might wanna think about an alert when too many bugs are produced in a given time period. And maybe an automatic kill-switch that e.g. reduces the max test cases of certain jobs.

I'll keep the max low until the end of the week because we have another noisy and spurious problem.

This is resolved. Switched back the max-testcases value for the job.