[Ada] Remove dead code from Enclosing_Package_Or_Subprogram routine

[Pierre-Marie de Rodat]

Calls to Scope always return unique entities, i.e. package/subprogram
and not their bodies, so there is no need to expect them.

Cleanup only; semantics unaffected. (This routine was only used in CCG
and GNATprove backends anyway.)

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

2019-07-08  Piotr Trojanek  <troja...@adacore.com>

gcc/ada/

        * sem_util.adb (Enclosing_Package_Or_Subprogram): Do not expect
        package and subprogram bodies.
--- gcc/ada/sem_util.adb
+++ gcc/ada/sem_util.adb
@@ -6924,12 +6924,7 @@ package body Sem_Util is
       S := Scope (E);
       while Present (S) loop
          if Is_Package_Or_Generic_Package (S)
-           or else Ekind (S) = E_Package_Body
-         then
-            return S;
-
-         elsif Is_Subprogram_Or_Generic_Subprogram (S)
-           or else Ekind (S) = E_Subprogram_Body
+           or else Is_Subprogram_Or_Generic_Subprogram (S)
          then
             return S;