Remove package imports from itself.

pkg/front_end/lib/src/fasta/scanner/recover.dart

 // Copyright (c) 2017, 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 licenset hat can be found in the LICENSE file.
 
 library fasta.scanner.recover;
 
 import 'token.dart' show StringToken, Token;
 
 import 'error_token.dart' show NonAsciiIdentifierToken, ErrorKind, ErrorToken;
 
 import 'precedence.dart' as Precedence;
 
 import 'precedence.dart' show PrecedenceInfo;
 
 /// Recover from errors in [tokens]. The original sources are provided as
 /// [bytes]. [lineStarts] are the beginning character offsets of lines, and
 /// must be updated if recovery is performed rewriting the original source
 /// code.
 Token defaultRecoveryStrategy(
     List<int> bytes, Token tokens, List<int> lineStarts) {
-  // See [Parser.reportErrorToken](package:front_end/src/fasta/parser/src/parser.dart) for how
+  // See [Parser.reportErrorToken](../parser/src/parser.dart) for how
   // it currently handles lexical errors. In addition, notice how the parser
   // calls [handleInvalidExpression], [handleInvalidFunctionBody], and
   // [handleInvalidTypeReference] to allow the listener to recover its internal
   // state. See [package:compiler/src/parser/element_listener.dart] for an
   // example of how these events are used.
   //
   // In addition, the scanner will attempt a bit of recovery when braces don't
   // match up during brace grouping. See
   // [ArrayBasedScanner.discardBeginGroupUntil](array_based_scanner.dart). For
   // more details on brace grouping see
@@ skipping 203 matching lines @@
 
 String closeBraceFor(String openBrace) {
   return const {
     '(': ')',
     '[': ']',
     '{': '}',
     '<': '>',
     r'${': '}',
   }[openBrace];
 }