Fix crash on access-to-incomplete type

This just adds the missing guard.

gcc/ada/
	PR ada/114708
	* exp_util.adb (Finalize_Address): Add guard for incomplete types.

gcc/testsuite/
	* gnat.dg/incomplete8.adb: New test.

gcc/ada/exp_util.adb

@@ -6076,6 +6076,12 @@ package body Exp_Util is
 
       Utyp := Underlying_Type (Base_Type (Utyp));
 
+      --  Handle incomplete types
+
+      if No (Utyp) then
+         return Empty;
+      end if;
+
       --  Deal with untagged derivation of private views. If the parent is
       --  now known to be protected, the finalization routine is the one
       --  defined on the corresponding record of the ancestor (corresponding

gcc/testsuite/gnat.dg/incomplete8.adb

@@ -0,0 +1,22 @@
+-- PR ada/114708
+-- Reported by Jere <jhb.chat@gmail.com>
+
+-- { dg-do compile }
+
+procedure Incomplete8 is
+
+  generic
+    type Element_Type(<>);
+  package Test_Incomplete_Formal is
+    type Element_Access is access Element_Type;
+  end Test_Incomplete_Formal;
+
+  type Node;
+
+  package P is new Test_Incomplete_Formal(Node);
+
+  type Node is limited null record;
+   
+begin
+  null;
+end;