Somehow emacs tries to unregister frame info for a symbol it did not register.

Don't abort for now. This worked before because the previous version of gcc
did not bother unregistering. Adding debugging printfs makes emacs core
dump, where other programs work fine.

external/gpl3/gcc/dist/gcc/unwind-dw2-fde.c

@@ -209,7 +209,9 @@ __deregister_frame_info_bases (const void *begin)
 
  out:
   __gthread_mutex_unlock (&object_mutex);
+#if 0
   gcc_assert (ob);
+#endif
   return (void *) ob;
 }