[Ada] Fix incorrect fixed-point computation in expression function

gcc/ada/

	* einfo.ads (E_Decimal_Fixed_Point_Subtype): Fix pasto.
	* freeze.adb (Freeze_Fixed_Point_Type): Retrieve the underlying type
	of the first subtype and do not use a stale value of Small_Value.
	* sem_res.adb (Resolve_Real_Literal): In the case of a fixed-point
	type, make sure that the base type is frozen and use its Small_Value
	to compute the corresponding integer value of the literal.

gcc/ada/einfo.ads

@@ -5353,7 +5353,7 @@ package Einfo is
    --    Size_Clause                           (synth)
 
    --  E_Decimal_Fixed_Point_Type
-   --  E_Decimal_Fixed_Subtype$$$no such thing
+   --  E_Decimal_Fixed_Point_Subtype
    --    Scale_Value
    --    Digits_Value
    --    Scalar_Range

gcc/ada/freeze.adb

@@ -8997,8 +8997,9 @@ package body Freeze is
       Brng  : constant Node_Id    := Scalar_Range (Btyp);
       BLo   : constant Node_Id    := Low_Bound (Brng);
       BHi   : constant Node_Id    := High_Bound (Brng);
-      Par   : constant Entity_Id  := First_Subtype (Typ);
-      Small : constant Ureal      := Small_Value (Typ);
+      Ftyp  : constant Entity_Id  := Underlying_Type (First_Subtype (Typ));
+
+      Small : Ureal;
       Loval : Ureal;
       Hival : Ureal;
       Atype : Entity_Id;
@@ -9037,7 +9038,7 @@ package body Freeze is
 
       function Larger (A, B : Ureal) return Boolean is
       begin
-         return A > B and then A - Small > B;
+         return A > B and then A - Small_Value (Typ) > B;
       end Larger;
 
       -------------
@@ -9046,7 +9047,7 @@ package body Freeze is
 
       function Smaller (A, B : Ureal) return Boolean is
       begin
-         return A < B and then A + Small < B;
+         return A < B and then A + Small_Value (Typ) < B;
       end Smaller;
 
    --  Start of processing for Freeze_Fixed_Point_Type
@@ -9057,9 +9058,15 @@ package body Freeze is
       --  so that all characteristics of the type (size, bounds) can be
       --  computed and validated in the call to Minimum_Size that follows.
 
-      if Has_Delayed_Aspects (First_Subtype (Typ)) then
-         Analyze_Aspects_At_Freeze_Point (First_Subtype (Typ));
-         Set_Has_Delayed_Aspects (First_Subtype (Typ), False);
+      if Has_Delayed_Aspects (Ftyp) then
+         Analyze_Aspects_At_Freeze_Point (Ftyp);
+         Set_Has_Delayed_Aspects (Ftyp, False);
+      end if;
+
+      --  Inherit the Small value from the first subtype in any case
+
+      if Typ /= Ftyp then
+         Set_Small_Value (Typ, Small_Value (Ftyp));
       end if;
 
       --  If Esize of a subtype has not previously been set, set it now
@@ -9074,16 +9081,6 @@ package body Freeze is
          end if;
       end if;
 
-      --  The 'small attribute may have been specified with an aspect,
-      --  in which case it is processed after a subtype declaration, so
-      --  inherit now the specified value.
-
-      if Typ /= Par
-        and then Present (Find_Aspect (Par, Aspect_Small))
-      then
-         Set_Small_Value (Typ, Small_Value (Par));
-      end if;
-
       --  Immediate return if the range is already analyzed. This means that
       --  the range is already set, and does not need to be computed by this
       --  routine.
@@ -9100,6 +9097,7 @@ package body Freeze is
          return;
       end if;
 
+      Small := Small_Value (Typ);
       Loval := Realval (Lo);
       Hival := Realval (Hi);
 
@@ -9137,7 +9135,6 @@ package body Freeze is
             Size_Excl_EP  : Int;
 
             Model_Num     : Ureal;
-            First_Subt    : Entity_Id;
             Actual_Lo     : Ureal;
             Actual_Hi     : Ureal;
 
@@ -9279,10 +9276,8 @@ package body Freeze is
                --  to get a base type whose size is smaller than the specified
                --  size of the first subtype.
 
-               First_Subt := First_Subtype (Typ);
-
-               if Has_Size_Clause (First_Subt)
-                 and then Size_Incl_EP <= Esize (First_Subt)
+               if Has_Size_Clause (Ftyp)
+                 and then Size_Incl_EP <= Esize (Ftyp)
                then
                   Actual_Size := Size_Incl_EP;
                   Actual_Lo   := Loval_Incl_EP;

gcc/ada/sem_res.adb

@@ -10765,17 +10765,23 @@ package body Sem_Res is
 
    begin
       --  Special processing for fixed-point literals to make sure that the
-      --  value is an exact multiple of small where this is required. We skip
-      --  this for the universal real case, and also for generic types.
+      --  value is an exact multiple of the small where this is required. We
+      --  skip this for the universal real case, and also for generic types.
 
       if Is_Fixed_Point_Type (Typ)
         and then Typ /= Universal_Fixed
         and then Typ /= Any_Fixed
         and then not Is_Generic_Type (Typ)
       then
+         --  We must freeze the base type to get the proper value of the small
+
+         if not Is_Frozen (Base_Type (Typ)) then
+            Freeze_Fixed_Point_Type (Base_Type (Typ));
+         end if;
+
          declare
             Val   : constant Ureal := Realval (N);
-            Cintr : constant Ureal := Val / Small_Value (Typ);
+            Cintr : constant Ureal := Val / Small_Value (Base_Type (Typ));
             Cint  : constant Uint  := UR_Trunc (Cintr);
             Den   : constant Uint  := Norm_Den (Cintr);
             Stat  : Boolean;