[Ada] Fix internal error on loop over array with misaligned index

[Eric Botcazou]

This is a regression present on the mainline.  The compiler aborts on a loop 
running over an array whose index type is a misaligned scalar type at -O3.

We're just forgetting to lift the padding type around the scalar type.

Tested on x86_64-suse-linux, applied on the mainline.


2013-06-03  Eric Botcazou  <ebotca...@adacore.com>

        * gcc-interface/trans.c (Raise_Error_to_gnu) <CE_Index_Check_Failed>:
        Record the unpadded type of the index type on the RCI stack.


2013-06-03  Eric Botcazou  <ebotca...@adacore.com>

        * gnat.dg/loop_optimization15.ad[sb]: New test.


-- 
Eric Botcazou
Index: gcc-interface/trans.c
===================================================================
--- gcc-interface/trans.c	(revision 196500)
+++ gcc-interface/trans.c	(working copy)
@@ -4944,7 +4944,7 @@ Raise_Error_to_gnu (Node_Id gnat_node, t
 	    {
 	      rci->low_bound = gnu_low_bound;
 	      rci->high_bound = gnu_high_bound;
-	      rci->type = gnat_to_gnu_type (gnat_type);
+	      rci->type = get_unpadded_type (gnat_type);
 	      rci->invariant_cond = build1 (SAVE_EXPR, boolean_type_node,
 					    boolean_true_node);
 	      gnu_cond = build_binary_op (TRUTH_ANDIF_EXPR,

-- { dg-do compile }
-- { dg-options "-O3" }

package body Loop_Optimization15 is

  type Integer_Array_T is array (B16_T range <>) of Integer;

  Len : constant B16_T := 10;

  Src : constant Integer_Array_T (1 .. Len) := (others => 0);
  Dst : Integer_Array_T (1 .. Len);

  procedure Proc (L : B16_T) is
  begin
      for I in  1 .. B16_T'Min (L, Len) loop
          Dst (I) := Src (I);
      end loop;
  end;

end Loop_Optimization15;

package Loop_Optimization15 is

  type B16_T is mod 2 ** 16;
  for B16_T'Size use 16;
  for B16_T'Alignment use 1;

  procedure Proc (L : B16_T);

end Loop_Optimization15;