Extract ReceiverMask interface from TypeMask.

pkg/compiler/lib/src/js_emitter/parameter_stub_generator.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.
 
 part of dart2js.js_emitter;
 
 class ParameterStubGenerator {
   static final Set<Selector> emptySelectorSet = new Set<Selector>();
 
   final Namer namer;
@@ skipping 182 matching lines @@
         compiler.internalError(cls.methodElement, 'Bound closure1.');
       }
       if (cls.methodElement.isInstanceMember) {
         compiler.internalError(cls.methodElement, 'Bound closure2.');
       }
     }
 
     // The set of selectors that apply to `member`. For example, for
     // a member `foo(x, [y])` the following selectors may apply:
     // `foo(x)`, and `foo(x, y)`.
-    Map<Selector, TypeMaskSet> selectors;
+    Map<Selector, ReceiverMaskSet> selectors;
     // The set of selectors that apply to `member` if it's name was `call`.
     // This happens when a member is torn off. In that case calls to the
     // function use the name `call`, and we must be able to handle every
     // `call` invocation that matches the signature. For example, for
     // a member `foo(x, [y])` the following selectors would be possible
     // call-selectors: `call(x)`, and `call(x, y)`.
-    Map<Selector, TypeMaskSet> callSelectors;
+    Map<Selector, ReceiverMaskSet> callSelectors;
 
     // Only instance members (not static methods) need stubs.
     if (member.isInstanceMember) {
         selectors = compiler.codegenWorld.invocationsByName(member.name);
     }
 
     if (canTearOff) {
       String call = namer.closureInvocationSelectorName;
       callSelectors = compiler.codegenWorld.invocationsByName(call);
     }
 
     assert(emptySelectorSet.isEmpty);
-    if (selectors == null) selectors = const <Selector, TypeMaskSet>{};
-    if (callSelectors == null) callSelectors = const <Selector, TypeMaskSet>{};
+    if (selectors == null) selectors = const <Selector, ReceiverMaskSet>{};
+    if (callSelectors == null) callSelectors =
+        const <Selector, ReceiverMaskSet>{};
 
     List<ParameterStubMethod> stubs = <ParameterStubMethod>[];
 
     if (selectors.isEmpty && callSelectors.isEmpty) {
       return stubs;
     }
 
     // For every call-selector the corresponding selector with the name of the
     // member.
     //
@@ skipping 39 matching lines @@
             generateParameterStub(member, selector, null);
         if (stub != null) {
           stubs.add(stub);
         }
       }
     }
 
     return stubs;
   }
 }