Support serialization of generic methods.

pkg/compiler/lib/src/serialization/equivalence.dart

 // Copyright (c) 2016, 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.
 
 /// Functions for asserting equivalence across serialization.
 
 library dart2js.serialization.equivalence;
 
 import '../closure.dart';
 import '../common.dart';
@@ skipping 544 matching lines @@
   bool visitMalformedType(MalformedType type, MalformedType other) => true;
 
   @override
   bool visitStatementType(StatementType type, StatementType other) {
     throw new UnsupportedError("Unsupported type: $type");
   }
 
   @override
   bool visitTypeVariableType(TypeVariableType type, TypeVariableType other) {
     return strategy.testElements(
-        type, other, 'element', type.element, other.element);
+        type, other, 'element', type.element, other.element) &&
+        strategy.test(type, other, 'is MethodTypeVariableType',
+            type is MethodTypeVariableType, other is MethodTypeVariableType);
   }
 
   @override
   bool visitVoidType(VoidType type, VoidType argument) => true;
 
   @override
   bool visitInterfaceType(InterfaceType type, InterfaceType other) {
     return visitGenericType(type, other);
   }
 
@@ skipping 1258 matching lines @@
 }
 
 bool areMetadataAnnotationsEquivalent(
     MetadataAnnotation metadata1, MetadataAnnotation metadata2) {
   if (metadata1 == metadata2) return true;
   if (metadata1 == null || metadata2 == null) return false;
   return areElementsEquivalent(
           metadata1.annotatedElement, metadata2.annotatedElement) &&
       areConstantsEquivalent(metadata1.constant, metadata2.constant);
 }