Introduce typed selectors to do better tree shaking based on calls on 'this'. Getters and setters w…

lib/compiler/implementation/enqueue.dart

 // Copyright (c) 2012, 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.
 
 class EnqueueTask extends CompilerTask {
   final Map<String, Link<Element>> instanceMembersByName;
   final Set<ClassElement> seenClasses;
 
   String get name() => 'Enqueue';
 
@@ skipping 54 matching lines @@
         member.kind === ElementKind.FIELD) {
       compiler.universe.instantiatedClassInstanceFields.add(member.name);
     }
 
     if (member.kind == ElementKind.FUNCTION) {
       if (member.name == Compiler.NO_SUCH_METHOD) {
         compiler.enableNoSuchMethod(member);
       }
       Set<Selector> selectors = compiler.universe.invokedNames[member.name];
       if (selectors != null) {
-        FunctionElement functionMember = member;
-        FunctionParameters parameters =
-            functionMember.computeParameters(compiler);
         for (Selector selector in selectors) {
-          if (selector.applies(parameters)) {
+          if (selector.applies(member, compiler)) {
             return compiler.addToWorkList(member);
           }
         }
       }
       // If there is a property access with the same name as a method we
       // need to emit the method.
       if (compiler.universe.invokedGetters.contains(member.name)) {
         // We will emit a closure, so make sure the closure class is
         // generated.
         compiler.closureClass.ensureResolved(compiler);
@@ skipping 77 matching lines @@
       instanceMembersByName[memberName] = remaining.toLink();
     }
   }
 
   void handleUnseenInvocation(SourceString methodName, Selector selector) {
     processInstanceMembers(methodName, (Element member) {
       if (member.isGetter()) {
         compiler.addToWorkList(member);
         return true;
       } else if (member.isFunction()) {
-        FunctionElement functionMember = member;
-        FunctionParameters parameters =
-          functionMember.computeParameters(compiler);
-        if (selector.applies(parameters)) {
+        if (selector.applies(member, compiler)) {
           compiler.addToWorkList(member);
           return true;
         }
       }
       return false;
     });
   }
 
   void handleUnseenGetter(SourceString methodName) {
     processInstanceMembers(methodName, (Element member) {
@@ skipping 10 matching lines @@
     processInstanceMembers(methodName, (Element member) {
       if (member.isSetter()) {
         compiler.addToWorkList(member);
         return true;
       } else {
         return false;
       }
     });
   }
 }