[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 #6 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
Created attachment 36995
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36995&action=edit
unreduced testcase

Started with r226861.