[Ada] Add Interface_Name field to E_Loop_Parameter

[Pierre-Marie de Rodat]

...for uniformity of referencing code.

Tested on x86_64-pc-linux-gnu, committed on trunk

gcc/ada/

        * gen_il-gen-gen_entities.adb (E_Loop_Parameter): Add
        Interface_Name field.
diff --git a/gcc/ada/gen_il-gen-gen_entities.adb b/gcc/ada/gen_il-gen-gen_entities.adb
--- a/gcc/ada/gen_il-gen-gen_entities.adb
+++ b/gcc/ada/gen_il-gen-gen_entities.adb
@@ -381,6 +381,7 @@ begin -- Gen_IL.Gen.Gen_Entities
        (Sm (Activation_Record_Component, Node_Id),
         Sm (Alignment, Uint),
         Sm (Esize, Uint),
+        Sm (Interface_Name, Node_Id),
         Sm (Is_Finalized_Transient, Flag),
         Sm (Is_Ignored_Transient, Flag),
         Sm (Linker_Section_Pragma, Node_Id),