[Bug c/97154] gcc/c/c-decl.c:5729:38: error: Dereference of an invalid iterator

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97154

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Though, sure, the code could use spec.back () != ' ' instead too.