[Bug lto/62026] [4.9/5 Regression] Crash in lto_get_decl_name_mapping

["hubicka at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62026

--- Comment #14 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
I am testing the following for 4.9-branch:
Index: cgraphclones.c
===================================================================
--- cgraphclones.c      (revision 215890)
+++ cgraphclones.c      (working copy)
@@ -310,6 +310,8 @@ duplicate_thunk_for_node (cgraph_node *t
   if (thunk_of->thunk.thunk_p)
     node = duplicate_thunk_for_node (thunk_of, node);

+  cgraph_get_body (thunk);
+
   struct cgraph_edge *cs;
   for (cs = node->callers; cs; cs = cs->next_caller)
     if (cs->caller->thunk.thunk_p
Index: lto-streamer-out.c
===================================================================
--- lto-streamer-out.c  (revision 215890)
+++ lto-streamer-out.c  (working copy)
@@ -2077,7 +2077,10 @@ lto_output (void)
 #endif
              decl_state = lto_new_out_decl_state ();
              lto_push_out_decl_state (decl_state);
-             if (gimple_has_body_p (node->decl) || !flag_wpa)
+             if (gimple_has_body_p (node->decl) || !flag_wpa
+                 /* Thunks have no body but they may be synthetized
+                    at WPA time.  */
+                 || DECL_ARGUMENTS (node->decl))
                output_function (node);
              else
                copy_function (node);