add an extra explicit step in initializing a drracket frame to set the toolbar buttons

closes PR 11608 (hopefully)

collects/drracket/private/module-language-tools.rkt

@@ -68,9 +68,11 @@
       ;; move button panel to the front of the list
       (send (get-button-panel) change-children 
             (λ (l) (cons toolbar-button-panel (remq toolbar-button-panel l))))
-      (let ([defs (get-definitions-text)])
-        (when (send defs get-in-module-language?)
-          (send defs move-to-new-language)))))
+      
+      (define/public (initialize-module-language)
+        (let ([defs (get-definitions-text)])
+          (when (send defs get-in-module-language?)
+            (send defs move-to-new-language))))))
   
   (define definitions-text<%> (interface ()))
   (define definitions-text-mixin

collects/drracket/private/unit.rkt

@@ -4696,6 +4696,7 @@ module browser threading seems wrong.
             (when pos
               (send frame move (car pos) (cdr pos)))))
         (send frame update-toolbar-visibility)
+        (send frame initialize-module-language)
         (send frame show #t)
         (send (send frame get-interactions-text) initialize-console)
         (set! first-frame? #f)