[Ada] Undefined symbol with interface types

[Arnaud Charlet]

Compiling with optimizations enabled the linker may report undefined
symbols of the form "xxxT<number>s" associated with types that implement
interface types. This issue was introduced on 2016-01-16 as part of
improving the support of subprograms that are inlined across units
with optimization.

No small reproducer available.

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

2016-05-02  Javier Miranda  <miranda@adacore.com>

	* exp_disp.adb (Make_Tags): Do not generate the
	external name of interface tags adding the suffix counter since
	it causes problems at link time when the IP routines are inlined
	across units with optimization.

-------------- next part --------------
Index: exp_disp.adb
===================================================================
--- exp_disp.adb	(revision 235706)
+++ exp_disp.adb	(working copy)
@@ -6,7 +6,7 @@
 --                                                                          --
 --                                 B o d y                                  --
 --                                                                          --
---          Copyright (C) 1992-2015, Free Software Foundation, Inc.         --
+--          Copyright (C) 1992-2016, Free Software Foundation, Inc.         --
 --                                                                          --
 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
 -- terms of the  GNU General Public License as published  by the Free Soft- --
@@ -6751,8 +6751,7 @@
                if Building_Static_DT (Typ) then
                   Iface_DT :=
                     Make_Defining_Identifier (Loc,
-                      Chars => New_External_Name
-                                 (Typ_Name, 'T', Suffix_Index => -1));
+                      Chars => New_External_Name (Typ_Name, 'T'));
                   Import_DT
                     (Tag_Typ => Related_Type (Node (AI_Tag_Comp)),
                      DT      => Iface_DT,