Implement noreturn procedure declarations

gcc/elna-generic.cc

@@ -256,6 +256,10 @@ namespace gcc
         tree fndecl = build_fn_decl(definition->identifier.c_str(), declaration_type);
         this->symbol_map->enter(definition->identifier, fndecl);
 
+        if (definition->no_return)
+        {
+            TREE_THIS_VOLATILE(fndecl) = 1;
+        }
         if (definition->body() != nullptr)
         {
             tree resdecl = build_decl(UNKNOWN_LOCATION, RESULT_DECL, NULL_TREE, return_type);

gcc/lang.opt

@@ -0,0 +1,23 @@
+; lang.opt -- Options for the Elna front end.
+; Copyright (C) 2025 Free Software Foundation, Inc.
+;
+; GCC is free software; you can redistribute it and/or modify it under
+; the terms of the GNU General Public License as published by the Free
+; Software Foundation; either version 3, or (at your option) any later
+; version.
+;
+; GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+; WARRANTY; without even the implied warranty of MERCHANTABILITY or
+; FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+; for more details.
+;
+; You should have received a copy of the GNU General Public License
+; along with GCC; see the file COPYING3.  If not see
+; <http://www.gnu.org/licenses/>.
+
+; See the GCC internals manual for a description of this file's format.
+
+; Please try to keep this file in ASCII collating order.
+
+Language
+Elna