https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64021
--- Comment #1 from Richard Henderson <rth at gcc dot gnu.org> --- Oh, that should read "fail after the merge of the new libffi". Current libffi happens to have nothing interesting in the stack slot that's incorrectly popped, and to happens not to fail. Not so with the ffi_call_go rewrite.