Attach type info to extension method and object method tear-offs

lib/src/codegen/js_codegen.dart

 // Copyright (c) 2015, 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.
 
 library dev_compiler.src.codegen.js_codegen;
 
 import 'dart:collection' show HashSet, HashMap, SplayTreeSet;
 
 import 'package:analyzer/analyzer.dart' hide ConstantEvaluator;
 import 'package:analyzer/src/generated/ast.dart' hide ConstantEvaluator;
@@ skipping 2438 matching lines @@
     }
     var name = _emitMemberName(memberId.name,
         type: getStaticType(target), isStatic: isStatic);
     if (DynamicInvoke.get(target)) {
       return js.call('dart.$DLOAD(#, #)', [_visit(target), name]);
     }
 
     String code;
     if (member != null && member is MethodElement && !isStatic) {
       // Tear-off methods: explicitly bind it.
-      // TODO(leafp): Attach runtime types to these static tearoffs
       if (_requiresStaticDispatch(target, memberId.name)) {
-        return js.call('dart.#.bind(#)', [name, _visit(target)]);
+        var type = member.type;
+        var clos = js.call('dart.#.bind(#)', [name, _visit(target)]);
+        return js.call('dart.fn(#, #)', [clos, _emitFunctionTypeParts(type)]);
       }
       code = 'dart.bind(#, #)';
     } else if (_requiresStaticDispatch(target, memberId.name)) {
       return js.call('dart.#(#)', [name, _visit(target)]);
     } else {
       code = '#.#';
     }
 
     return js.call(code, [_visit(target), name]);
   }
@@ skipping 602 matching lines @@
 
 /// A special kind of element created by the compiler, signifying a temporary
 /// variable. These objects use instance equality, and should be shared
 /// everywhere in the tree where they are treated as the same variable.
 class TemporaryVariableElement extends LocalVariableElementImpl {
   TemporaryVariableElement.forNode(Identifier name) : super.forNode(name);
 
   int get hashCode => identityHashCode(this);
   bool operator ==(Object other) => identical(this, other);
 }