Support self-referential package: imports with Pub.

utils/tests/pub/version_solver_test.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('pub_update_test');
 
 #import('dart:io');
 #import('dart:isolate');
 
 #import('../../pub/lock_file.dart');
@@ skipping 389 matching lines @@
   Package mockPackage(String description, String version,
       Map dependencyStrings) {
     // Build the pubspec dependencies.
     var dependencies = <PackageRef>[];
     dependencyStrings.forEach((name, constraint) {
       var parsed = parseSource(name);
       dependencies.add(new PackageRef(
           parsed.last, new VersionConstraint.parse(constraint), parsed.first));
     });
 
-    var pubspec = new Pubspec(new Version.parse(version), dependencies);
-    return new Package.inMemory(description, pubspec);
+    var pubspec = new Pubspec(
+        description, new Version.parse(version), dependencies);
+    return new Package.inMemory(pubspec);
   }
 
   void addPackage(Package package) {
     _packages.putIfAbsent(package.name, () => new Map<Version, Package>());
     _packages[package.name][package.version] = package;
   }
 
   String packageName(String description) =>
     description.replaceFirst(new RegExp(@"-[^-]+$"), "");
 }
@@ skipping 36 matching lines @@
 Pair<String, Source> parseSource(String name) {
   var match = new RegExp(@"(.*) from (.*)").firstMatch(name);
   if (match == null) return new Pair<String, Source>(name, source1);
   switch (match[2]) {
   case 'mock1': return new Pair<String, Source>(match[1], source1);
   case 'mock2': return new Pair<String, Source>(match[1], source2);
   case 'versionless':
     return new Pair<String, Source>(match[1], versionlessSource);
   }
 }