[Ada] Spurious visibility error on Declare_Expression with renames

[Pierre-Marie de Rodat]

The compiler rejects a declare expression whose declarations are only
object renaming declarations, when the expression references those
local objects.

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

gcc/ada/

        * sem_res.adb (Resolve_Declare_Expression): Retrieve the created
        block entity that is the scope of the local declarations, from
        either a local object declaration or an object renaming
        declaration. The block entity does not have an explicit
        declaration, but appears as the scope of all locally declared
        objects.
diff --git a/gcc/ada/sem_res.adb b/gcc/ada/sem_res.adb
--- a/gcc/ada/sem_res.adb
+++ b/gcc/ada/sem_res.adb
@@ -7441,11 +7441,14 @@ package body Sem_Res is
       --  Install the scope created for local declarations, if
       --  any. The syntax allows a Declare_Expression with no
       --  declarations, in analogy with block statements.
+      --  Note that that scope has no explicit declaration, but
+      --  appears as the scope of all entities declared therein.
 
       Decl := First (Actions (N));
 
       while Present (Decl) loop
-         exit when Nkind (Decl) = N_Object_Declaration;
+         exit when Nkind (Decl)
+                     in N_Object_Declaration | N_Object_Renaming_Declaration;
          Next (Decl);
       end loop;