Clean up package imports and library names

pkg/analyzer/lib/src/generated/java_core.dart

-library java.core;
+// 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.
+
+library analyzer.src.generated.java_core;
 
 const int LONG_MAX_VALUE = 0x7fffffffffffffff;
 
 final Stopwatch nanoTimeStopwatch = new Stopwatch();
 
 /**
  * Inserts the given arguments into [pattern].
  *
  *     format('Hello, {0}!', 'John') = 'Hello, John!'
  *     format('{0} are you {1}ing?', 'How', 'do') = 'How are you doing?'
@@ skipping 425 matching lines @@
 
 class UnsupportedOperationException extends JavaException {
   UnsupportedOperationException([message = ""]) : super(message);
 }
 
 class URISyntaxException implements Exception {
   final String message;
   URISyntaxException(this.message);
   String toString() => "URISyntaxException: $message";
 }