[Ada] Remove new problematic condition for LLVM

[Pierre-Marie de Rodat]

The new condition added for scalar types in the previous change for
the sake of consistency with array types is apparently problematic
for LLVM so this change removes it.

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

2020-06-17  Eric Botcazou  <ebotca...@adacore.com>

gcc/ada/

        * exp_attr.adb (Expand_N_Attribute_Reference) <Attribute_First>:
        Remove condition added for scalar types.
--- gcc/ada/exp_attr.adb
+++ gcc/ada/exp_attr.adb
@@ -3470,9 +3470,7 @@ package body Exp_Attr is
                   Bnd := Type_High_Bound (Ptyp);
                end if;
 
-               if Is_Entity_Name (Bnd)
-                 and then Ekind (Entity (Bnd)) /= E_Discriminant
-               then
+               if Is_Entity_Name (Bnd) then
                   Rewrite (N, New_Occurrence_Of (Entity (Bnd), Loc));
                end if;
             end;