https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116410
--- Comment #10 from Sam James <sjames at gcc dot gnu.org> --- r11-5517-g3350e59f298546 and r11-5061-g85ebbabd85e03b, but we added modref in r11-3308-gd119f34c952f87 (so it was broken from the start)