[COMMITTED] ada: Fix Program_Error raised during generation of data representation in JSON

[Marc Poulhiès]

From: Eric Botcazou <ebotca...@adacore.com>

This happens for the extension of a private discriminated tagged type.

gcc/ada/

        * repinfo.adb (List_Record_Info.List_Structural_Record_Layout): Add
        another guard for private types after retrieving the parent in the
        extension case.

Tested on x86_64-pc-linux-gnu, committed on master.

---
 gcc/ada/repinfo.adb | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/gcc/ada/repinfo.adb b/gcc/ada/repinfo.adb
index 28a587f039b..28e4a642765 100644
--- a/gcc/ada/repinfo.adb
+++ b/gcc/ada/repinfo.adb
@@ -1491,6 +1491,12 @@ package body Repinfo is
 
                   else
                      Parent_Type := Base_Type (Parent_Type);
+
+                     if Is_Private_Type (Parent_Type) then
+                        Parent_Type := Full_View (Parent_Type);
+                        pragma Assert (Present (Parent_Type));
+                     end if;
+
                      if not In_Extended_Main_Source_Unit (Parent_Type) then
                         raise Not_In_Extended_Main;
                      end if;
-- 
2.43.2