Remove deprecated_warning.

pkg/front_end/messages.yaml

 # Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 # Each entry in this map corresponds to a diagnostic message. Ideally, each
 # entry contains three parts:
 #
 # 1. A message template (template).
 #
 # 2. A suggestion for how to correct the problem (tip).
@@ skipping 798 matching lines @@
   template: "Expected identifier, but got 'super'."
 
 SwitchCaseFallThrough:
   template: "Switch case may fall through to next case."
 
 FinalInstanceVariableAlreadyInitialized:
   template: "'#name' is final instance variable that has already been initialized."
 
 FinalInstanceVariableAlreadyInitializedCause:
   template: "'#name' was initialized here."
+
+TypeVariableInStaticContext:
+  template: "Type variables can't be used in static members."
+
+SuperclassMethodArgumentMismatch:
+  template: "Superclass doesn't have a method named '#name' with matching arguments."
+
+SuperclassHasNoGetter:
+  template: "Superclass has no getter named '#name'."
+
+SuperclassHasNoSetter:
+  template: "Superclass has no setter named '#name'."
+
+SuperclassHasNoMethod:
+  template: "Superclass has no method named '#name'."