https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77333
--- Comment #9 from Tony Kelman <tony at kelman dot net> --- How can we help get this moving towards resolution? This has kept us stuck on GCC 4.9, which is getting increasingly problematic. We can attempt to reduce this to "minimal working piece of opt.exe with gcc 4.9" vs "broken equivalent piece with gcc 5+," but given the IPA nature of r217587 I'm not sure how that will go.
