https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89459
--- Comment #3 from joseph at codesourcery dot com <joseph at codesourcery dot com> --- GCC 8 branched off mainline in April 2018, long before that merge; it's necessary to test mainline (that will become GCC 9 and later), not any existing release, to see if that merge fixed things.
