[Ada] Reuse Has_Defaulted_Discriminants where possible

diff --git a/gcc/ada/exp_attr.adb b/gcc/ada/exp_attr.adb
--- a/gcc/ada/exp_attr.adb
+++ b/gcc/ada/exp_attr.adb
@@ -6115,10 +6115,7 @@  package body Exp_Attr is
                   return;
                end if;
 
-               if Has_Discriminants (U_Type)
-                 and then Present
-                   (Discriminant_Default_Value (First_Discriminant (U_Type)))
-               then
+               if Has_Defaulted_Discriminants (U_Type) then
                   Build_Mutable_Record_Read_Procedure
                     (Loc, Full_Base (U_Type), Decl, Pname);
                else
@@ -7750,10 +7747,7 @@  package body Exp_Attr is
                   end if;
                end if;
 
-               if Has_Discriminants (U_Type)
-                 and then Present
-                   (Discriminant_Default_Value (First_Discriminant (U_Type)))
-               then
+               if Has_Defaulted_Discriminants (U_Type) then
                   Build_Mutable_Record_Write_Procedure
                     (Loc, Full_Base (U_Type), Decl, Pname);
                else


diff --git a/gcc/ada/exp_ch9.adb b/gcc/ada/exp_ch9.adb
--- a/gcc/ada/exp_ch9.adb
+++ b/gcc/ada/exp_ch9.adb
@@ -13972,9 +13972,7 @@  package body Exp_Ch9 is
    begin
       return Scope (Base_Index) = Standard_Standard
         and then Base_Index = Base_Type (Standard_Integer)
-        and then Has_Discriminants (Conctyp)
-        and then
-          Present (Discriminant_Default_Value (First_Discriminant (Conctyp)))
+        and then Has_Defaulted_Discriminants (Conctyp)
         and then
           (Denotes_Discriminant (Lo, True)
              or else


diff --git a/gcc/ada/sem_ch3.adb b/gcc/ada/sem_ch3.adb
--- a/gcc/ada/sem_ch3.adb
+++ b/gcc/ada/sem_ch3.adb
@@ -13971,9 +13971,7 @@  package body Sem_Ch3 is
           (Has_Unknown_Discriminants (T)
             or else
               (not Has_Discriminants (T)
-                and then Has_Discriminants (Full_View (T))
-                and then Present (Discriminant_Default_Value
-                           (First_Discriminant (Full_View (T))))))
+                and then Has_Defaulted_Discriminants (Full_View (T))))
       then
          T := Full_View (T);
          E := Full_View (E);
@@ -20805,9 +20803,7 @@  package body Sem_Ch3 is
 
       if not Has_Unknown_Discriminants (Priv_T)
         and then not Has_Discriminants (Priv_T)
-        and then Has_Discriminants (Full_T)
-        and then
-          Present (Discriminant_Default_Value (First_Discriminant (Full_T)))
+        and then Has_Defaulted_Discriminants (Full_T)
       then
          Set_Has_Constrained_Partial_View (Full_T);
          Set_Has_Constrained_Partial_View (Priv_T);


diff --git a/gcc/ada/sem_ch4.adb b/gcc/ada/sem_ch4.adb
--- a/gcc/ada/sem_ch4.adb
+++ b/gcc/ada/sem_ch4.adb
@@ -599,12 +599,8 @@  package body Sem_Ch4 is
                Type_Id := Entity (E);
 
                if Is_Tagged_Type (Type_Id)
-                 and then Has_Discriminants (Type_Id)
+                 and then Has_Defaulted_Discriminants (Type_Id)
                  and then not Is_Constrained (Type_Id)
-                 and then
-                   Present
-                     (Discriminant_Default_Value
-                       (First_Discriminant (Type_Id)))
                then
                   declare
                      Constr : constant List_Id    := New_List;
@@ -612,19 +608,17 @@  package body Sem_Ch4 is
                      Discr  : Entity_Id := First_Discriminant (Type_Id);
 
                   begin
-                     if Present (Discriminant_Default_Value (Discr)) then
-                        while Present (Discr) loop
-                           Append (Discriminant_Default_Value (Discr), Constr);
-                           Next_Discriminant (Discr);
-                        end loop;
+                     while Present (Discr) loop
+                        Append (Discriminant_Default_Value (Discr), Constr);
+                        Next_Discriminant (Discr);
+                     end loop;
 
-                        Rewrite (E,
-                          Make_Subtype_Indication (Loc,
-                            Subtype_Mark => New_Occurrence_Of (Type_Id, Loc),
-                            Constraint   =>
-                              Make_Index_Or_Discriminant_Constraint (Loc,
-                                Constraints => Constr)));
-                     end if;
+                     Rewrite (E,
+                       Make_Subtype_Indication (Loc,
+                         Subtype_Mark => New_Occurrence_Of (Type_Id, Loc),
+                         Constraint   =>
+                           Make_Index_Or_Discriminant_Constraint (Loc,
+                             Constraints => Constr)));
                   end;
                end if;
             end if;


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
@@ -11818,7 +11818,6 @@  package body Sem_Util is
    function Has_Defaulted_Discriminants (Typ : Entity_Id) return Boolean is
    begin
       return Has_Discriminants (Typ)
-       and then Present (First_Discriminant (Typ))
        and then Present (Discriminant_Default_Value
                            (First_Discriminant (Typ)));
    end Has_Defaulted_Discriminants;
@@ -17141,9 +17140,7 @@  package body Sem_Util is
       --  Record types
 
       elsif Is_Record_Type (Typ) then
-         if Has_Discriminants (Typ)
-           and then
-             Present (Discriminant_Default_Value (First_Discriminant (Typ)))
+         if Has_Defaulted_Discriminants (Typ)
            and then Is_Fully_Initialized_Variant (Typ)
          then
             return True;