Introduce typed selectors for getters and setters also for better tree shaking.

lib/compiler/implementation/elements/elements.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.
 
 #library('elements');
 
 #import('../tree/tree.dart');
 #import('../scanner/scannerlib.dart');
 #import('../leg.dart');  // TODO(karlklose): we only need type.
 #import('../util/util.dart');
@@ skipping 108 matching lines @@
   bool isCompilationUnit() {
     return kind === ElementKind.COMPILATION_UNIT ||
            kind === ElementKind.LIBRARY;
   }
   bool isClass() => kind === ElementKind.CLASS;
   bool isVariable() => kind === ElementKind.VARIABLE;
   bool isParameter() => kind === ElementKind.PARAMETER;
   bool isStatement() => kind === ElementKind.STATEMENT;
   bool isTypedef() => kind === ElementKind.TYPEDEF;
   bool isTypeVariable() => kind === ElementKind.TYPE_VARIABLE;
+  bool isField() => kind === ElementKind.FIELD;
   bool isGetter() => kind === ElementKind.GETTER;
   bool isSetter() => kind === ElementKind.SETTER;
   bool impliesType() => (kind.category & ElementCategory.IMPLIES_TYPE) != 0;
   bool isExtendable() => (kind.category & ElementCategory.IS_EXTENDABLE) != 0;
 
   bool isAssignable() {
     if (modifiers != null && modifiers.isFinal()) return false;
     if (isFunction() || isGenerativeConstructor()) return false;
     return true;
   }
@@ skipping 906 matching lines @@
   final Node node;
   Type bound;
   Type type;
   TypeVariableElement(name, Element enclosing, this.node, this.type,
                       [this.bound])
     : super(name, ElementKind.TYPE_VARIABLE, enclosing);
   Type computeType(compiler) => type;
   Node parseNode(compiler) => node;
   toString() => "${enclosingElement.toString()}.${name.slowToString()}";
 }