[Bug c++/70847] [6/7 Regression] exponential time in cp_fold for chained virtual function calls

[sirl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70847

--- Comment #9 from Franz Sirl <sirl at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #7)
> Created attachment 38636 [details]
> gcc7-pr70847.patch
> 
> Untested fix.

Applied to gcc-6-branch r237059, no testsuite regressions. Testcase from
comment 6 and original codebase back to normal compile times.