Issue 8742. Preserve leading line comments during java2dart translation.

pkg/analyzer/lib/src/generated/error.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.
 
 // This code was auto-generated, is not intended to be edited, and is subject to
 // significant change. Please see the README file for more information.
 
 library engine.error;
 
 import 'java_core.dart';
@@ skipping 422 matching lines @@
     String correctionTemplate = errorCode.correction;
     if (correctionTemplate != null) {
       this._correction = JavaString.format(correctionTemplate, arguments);
     }
   }
 
   bool operator ==(Object obj) {
     if (identical(obj, this)) {
       return true;
     }
+    // prepare other AnalysisError
     if (obj is! AnalysisError) {
       return false;
     }
     AnalysisError other = obj as AnalysisError;
+    // Quick checks.
     if (errorCode != other.errorCode) {
       return false;
     }
     if (_offset != other._offset || _length != other._length) {
       return false;
     }
     if (isStaticOnly != other.isStaticOnly) {
       return false;
     }
+    // Deep checks.
     if (_message != other._message) {
       return false;
     }
     if (source != other.source) {
       return false;
     }
+    // OK
     return true;
   }
 
   /**
    * Return the correction to be displayed for this error, or `null` if there is no correction
    * information for this error. The correction should indicate how the user can fix the error.
    *
    * @return the template used to create the correction to be displayed for this error
    */
   String get correction => _correction;
@@ skipping 39 matching lines @@
   }
 
   String toString() {
     JavaStringBuilder builder = new JavaStringBuilder();
     builder.append((source != null) ? source.fullName : "<unknown source>");
     builder.append("(");
     builder.append(_offset);
     builder.append("..");
     builder.append(_offset + _length - 1);
     builder.append("): ");
+    //builder.append("(" + lineNumber + ":" + columnNumber + "): ");
     builder.append(_message);
     return builder.toString();
   }
 }
 
 /**
  * The enumeration `ErrorProperty` defines the properties that can be associated with an
  * [AnalysisError].
  */
 class ErrorProperty extends Enum<ErrorProperty> {
@@ skipping 3105 matching lines @@
   StaticTypeWarningCode.con2(String name, int ordinal, this.message, String correction) : super(name, ordinal) {
     this.correction7 = correction;
   }
 
   String get correction => correction7;
 
   ErrorSeverity get errorSeverity => ErrorType.STATIC_TYPE_WARNING.severity;
 
   ErrorType get type => ErrorType.STATIC_TYPE_WARNING;
 }