Support abstract getters without parameters.

dart/lib/compiler/implementation/compile_time_constants.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 Constant implements Hashable {
   const Constant();
 
   bool isNull() => false;
   bool isBool() => false;
   bool isTrue() => false;
@@ skipping 16 matching lines @@
   /**
     * Unless the constant can be emitted multiple times (as for numbers and
     * strings) adds its canonical name to the buffer.
     */
   abstract void _writeCanonicalizedJsCode(CodeBuffer buffer,
                                           ConstantHandler handler);
   abstract List<Constant> getDependencies();
 }
 
 class PrimitiveConstant extends Constant {
-  abstract get value();
+  abstract get value;
   const PrimitiveConstant();
   bool isPrimitive() => true;
 
   bool operator ==(var other) {
     if (other is !PrimitiveConstant) return false;
     PrimitiveConstant otherPrimitive = other;
     // We use == instead of === so that DartStrings compare correctly.
     return value == otherPrimitive.value;
   }
 
@@ skipping 19 matching lines @@
   void _writeJsCode(CodeBuffer buffer, ConstantHandler handler) {
     buffer.add(JsNull);
   }
 
   // The magic constant has no meaning. It is just a random value.
   int hashCode() => 785965825;
   DartString toDartString() => const LiteralDartString("null");
 }
 
 class NumConstant extends PrimitiveConstant {
-  abstract num get value();
+  abstract num get value;
   const NumConstant();
   bool isNum() => true;
 }
 
 class IntConstant extends NumConstant {
   final int value;
   factory IntConstant(int value) {
     switch (value) {
       case 0: return const IntConstant._internal(0);
       case 1: return const IntConstant._internal(1);
@@ skipping 1082 matching lines @@
       Constant fieldValue = fieldValues[field];
       if (fieldValue === null) {
         // Use the default value.
         fieldValue = compiler.compileVariable(field);
       }
       jsNewArguments.add(fieldValue);
     });
     return jsNewArguments;
   }
 }