[Ada] Assert failure on b38105a in -gnat95 mode

[Pierre-Marie de Rodat]

A cascaded error leads to some confusion in this case, fixed by making
Inherit_Predicate_Flags a no-op pre Ada 2012.

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

gcc/ada/

        * sem_util.adb (Inherit_Predicate_Flags): No-op before Ada 2012.
diff --git a/gcc/ada/sem_util.adb b/gcc/ada/sem_util.adb
--- a/gcc/ada/sem_util.adb
+++ b/gcc/ada/sem_util.adb
@@ -14625,7 +14625,9 @@ package body Sem_Util is
 
    procedure Inherit_Predicate_Flags (Subt, Par : Entity_Id) is
    begin
-      if Present (Predicate_Function (Subt)) then
+      if Ada_Version < Ada_2012
+        or else Present (Predicate_Function (Subt))
+      then
          return;
       end if;