Split scannerlib.dart into several libraries.

pkg/compiler/lib/src/scanner/scanner.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.
 
-part of scanner;
+library dart2js.scanner;
+
+import '../io/source_file.dart' show
+    SourceFile,
+    Utf8BytesSourceFile;
+import '../util/characters.dart';
+
+import 'keyword.dart' show
+    Keyword,
+    KeywordState;
+import 'string_scanner.dart' show
+    StringScanner;
+import 'token.dart';
+import 'utf8_bytes_scanner.dart' show
+    Utf8BytesScanner;
+
 
 abstract class Scanner {
   Token tokenize();
 
   factory Scanner(SourceFile file,
       {bool includeComments: false}) {
     if (file is Utf8BytesSourceFile) {
       return new Utf8BytesScanner(file, includeComments: includeComments);
     } else {
       return new StringScanner(file, includeComments: includeComments);
@@ skipping 1146 matching lines @@
 
 PrecedenceInfo closeBraceInfoFor(BeginGroupToken begin) {
   return const {
     '(': CLOSE_PAREN_INFO,
     '[': CLOSE_SQUARE_BRACKET_INFO,
     '{': CLOSE_CURLY_BRACKET_INFO,
     '<': GT_INFO,
     r'${': CLOSE_CURLY_BRACKET_INFO,
   }[begin.value];
 }