[Bug tree-optimization/68853] [6 Regression] gcc-6 miscompiles Chromium v8 garbage collector

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68853

--- Comment #4 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #3)
> Can you bisect it to the alias changes from Honza or is this older?

The first issue is older. At least a few weeks.
I don't have a powerful enough machine to bisect this and the 
compile farm machines cannot build Chromium, because of missing
libraries. 
(I've seen the second issue for the first time today.)

> Is this  part of chromium single-threaded?

If you start chromium with:
 google-chrome --no-sandbox --renderer-cmd-prefix='xterm -title renderer -e gdb
-ex run --args'
it will attach a debugger to every started thread.
The segfault happens in one of them.