[NF] Relax connector check for e.g. isRoot.

- Allow A in A.R to be a qualified cref.

Belonging to [master]:
  - #2618

Author: perost

Compiler/NFFrontEnd/NFBuiltinCall.mo

@@ -1482,8 +1482,7 @@ protected
                 restCref = ComponentRef.CREF(ty = ty2, origin = NFComponentRef.Origin.CREF,
                 restCref = rest_cref))
               then Class.isOverdetermined(InstNode.getClass(node)) and
-                   Type.isConnector(ty2) and
-                   not ComponentRef.isFromCref(rest_cref);
+                   Type.isConnector(ty2);
 
             else false;
           end match;