Compile implicit closures as dispatchers instead of duplicating the original method's code.

tests/standalone/full_coverage_test.dart

 // Copyright (c) 2014, 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.
 
 // These tests fork a second VM process that runs the script
 // ``tools/full-coverage.dart'' and verifies that the tool
 // produces the expeced output.
 
 import 'dart:async';
 import 'dart:convert';
@@ skipping 31 matching lines @@
 }
 
 main() {
   if (false) {
     dummy(11);
   } else {
     fac(10);
   }
 }
 ''',
-    'expectedHits': [-1, 0, 0, -1, -1, -1, -1, -1, 1, 1, -1, -1, -1, -1, -1, -1,
+    'expectedHits': [-1, 0, 0, -1, -1, -1, -1, -1, 1, 1, -1, -1, -1, -1, 1, -1,
                      0, -1, 1, -1, -1]
   },{
     'name': 'closures',
     'program': '''
 main() {
   foo(bar) {
     bar();
   }
 
   foo(() {
     print("in closure");
   });
 }
 ''',
-    'expectedHits': [-1, -1, 1, -1, -1, 1, 1, -1, -1]
+    'expectedHits': [1, -1, 1, -1, -1, 1, 1, -1, -1]
   }
 ];
 
 
 String prepareEnv() {
   Directory testDir = Directory.systemTemp.createTempSync("coverage-");
   for (var coverageProg in coverageTests) {
     var coverageProgDir = new Directory(
         path.join(testDir.path, coverageProg["name"]))
       ..createSync();
@@ skipping 145 matching lines @@
       String programPath = path.join(programDir, "${cTest['name']}.dart");
       testCoverage(programDir, programPath,
                    new LcovDescriptor(programPath),
                    new List.from(cTest['expectedHits']));
       testCoverage(programDir, programPath,
                    new PrettyPrintDescriptor(programPath),
                    new List.from(cTest['expectedHits']));
     });
   });
 }