opt62.adb: New test.

	* gnat.dg/opt62.adb: New test.
	* gnat.dg/opt62_pkg.ads: New helper.

From-SVN: r244485

gcc/testsuite/ChangeLog

+2017-01-16  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gnat.dg/opt62.adb: New test.
+	* gnat.dg/opt62_pkg.ads: New helper.
+
 2017-01-14  Bernd Schmidt  <bschmidt@redhat.com>
 
         PR rtl-optimization/78626

gcc/testsuite/gnat.dg/opt62.adb

+-- { dg-do run }
+-- { dg-options "-O" }
+
+with Opt62_Pkg; use Opt62_Pkg;
+
+procedure Opt62 is
+
+   String5  : String(1..5)  := "12345";
+   D: Der := (Unconstrained_Der with D2 => 5, S2 => String5);
+
+begin
+   if D.Str1 /= "abcde" then
+      raise Program_Error;
+   end if;
+end;

gcc/testsuite/gnat.dg/opt62_pkg.ads

+package Opt62_Pkg is
+
+   Default_String : constant String := "This is a default string";
+
+   subtype Length is Natural range 0..255;
+
+   type Root (D1 : Length) is tagged  record
+      S1  : String(1..D1) := Default_String(1..D1);
+   end record;
+
+   type Unconstrained_Der is new Root with  record
+      Str1 : String(1..5) := "abcde";
+   end record;
+
+   type Der (D2 : Length) is new Unconstrained_Der (D1 => 10) with record
+      S2 : String(1..D2);
+   end record;
+
+end Opt62_Pkg;