[Ada] Fix bogus error for 'Unrestricted_Access of overloaded subprogram

[Eric Botcazou]

This plugs an old loophole in Analyze_Attribute for the handling of the GNAT 
specific Unrestricted_Access attribute.

Tested on x86-64/Linux, applied on the mainline and 16 branch.


2026-07-30  Eric Botcazou  <ebotca...@adacore.com>

        PR ada/126482
        * sem_attr.adb (Analyze_Attribute): Treat Unrestricted_Access like
        [Unchecked_]Access when it comes to the overloading of the prefix.

-- 
Eric Botcazou
diff --git a/gcc/ada/sem_attr.adb b/gcc/ada/sem_attr.adb
index 7ef0145e872..7180ab81314 100644
--- a/gcc/ada/sem_attr.adb
+++ b/gcc/ada/sem_attr.adb
@@ -3527,6 +3527,7 @@ package body Sem_Attr is
         and then Aname /= Name_Code_Address
         and then Aname /= Name_Result
         and then Aname /= Name_Unchecked_Access
+        and then Aname /= Name_Unrestricted_Access
       then
          --  The prefix must be resolvable by itself, without reference to the
          --  attribute. One case that requires special handling is a prefix