[Ada] Ease interface with builtins that returns void *

[Arnaud Charlet]

The natural way to import a builtin that returns void * is to use
System.Address in Ada, which is in fact an integral type.

Addressed by this patch, which makes it possible to e.g. compile:

with System;
procedure Btins1 is

   function Frame_Address (Level : Integer) return System.Address;
   pragma Import (Intrinsic, Frame_Address, "__builtin_frame_address");

   Ptr : System.Address;
   pragma Volatile (Ptr);
begin
   Ptr := Frame_Address (0);
end;

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

2012-07-16  Tristan Gingold  <gingold@adacore.com>
        
	* gcc-interface/decl.c (intrin_return_compatible_p): Map Address to     
	void *.

-------------- next part --------------
Index: gcc-interface/decl.c
===================================================================
--- gcc-interface/decl.c	(revision 189524)
+++ gcc-interface/decl.c	(working copy)
@@ -8046,6 +8046,10 @@
       && !VOID_TYPE_P (btin_return_type))
     return true;
 
+  /* If return type is Address (integer type), map it to void *.  */
+  if (Is_Descendent_Of_Address (Etype (inb->gnat_entity)))
+    ada_return_type = ptr_void_type_node;
+
   /* Check return types compatibility otherwise.  Note that this
      handles void/void as well.  */
   if (intrin_types_incompatible_p (btin_return_type, ada_return_type))