make ExecuTorch program always has valid debug handle map and delegate map

Differential Revision: D79706058

Pull Request resolved: pytorch#13149

Author: Gasoonjia

exir/program/_program.py

@@ -613,15 +613,15 @@ def program(self) -> Program:
     def debug_handle_map(self) -> Dict[int, Union[int, List[int]]]:
         if self._emitter_output:
             return self._emitter_output.debug_handle_map
-        return {}
+        return self._get_emitter_output().debug_handle_map
 
     @property
     def delegate_map(
         self,
     ) -> Dict[str, Dict[int, Dict[str, Union[str, _DelegateDebugIdentifierMap]]]]:
         if self._emitter_output:
             return self._emitter_output.method_to_delegate_debug_id_map
-        return {}
+        return self._get_emitter_output().method_to_delegate_debug_id_map
 
     @property
     def graph_module(self) -> torch.fx.GraphModule: