https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89592
--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Confirmed it is this revision even on the runtime testcase from struct-layout-1.exp testing. The question is what if anything the psABI says here, what do other compilers do etc. Passing flexible array members as values isn't the best documented thing in the ABIs...