https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51577
--- Comment #17 from Nathan Sidwell <nathan at gcc dot gnu.org> --- ah, the logic to squirrel away lookups on a magic attribute list, records that nothing is found. But we don't preserve that negative lookup when injecting these lookups into the parameter binding. So we'll end up finding later-declared namespace-scope entities.
