Fix reparent on windows

pkg/analysis_server/lib/src/services/correction/assist_internal.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.
 
 library services.src.correction.assist;
 
 import 'dart:async';
 import 'dart:collection';
 
 import 'package:analysis_server/plugin/edit/assist/assist_core.dart';
@@ skipping 1754 matching lines @@
     }
     String newExprSrc = utils.getNodeText(newExpr);
     SourceBuilder sb = new SourceBuilder(file, newExpr.offset);
     sb.append('new ');
     sb.startPosition('WIDGET');
     sb.append('widget');
     sb.endPosition();
     sb.append('(');
     if (newExprSrc.contains(eol)) {
       int newlineIdx = newExprSrc.lastIndexOf(eol);
-      if (newlineIdx == newExprSrc.length - 1) {
-        newlineIdx -= 1;
+      int eolLen = eol.length;
+      if (newlineIdx == newExprSrc.length - eolLen) {
+        newlineIdx -= eolLen;
       }
-      String indentOld = utils.getLinePrefix(newExpr.offset + 1 + newlineIdx);
+      String indentOld =
+          utils.getLinePrefix(newExpr.offset + eolLen + newlineIdx);
       String indentNew = '$indentOld${utils.getIndent(1)}';
       sb.append(eol);
       sb.append(indentNew);
       newExprSrc = newExprSrc.replaceAll(
           new RegExp("^$indentOld", multiLine: true), "$indentNew");
       newExprSrc += ",$eol$indentOld";
     }
     sb.startPosition('CHILD');
     sb.append('child');
     sb.endPosition();
@@ skipping 760 matching lines @@
 class _SimpleIdentifierRecursiveAstVisitor extends RecursiveAstVisitor {
   final _SimpleIdentifierVisitor visitor;
 
   _SimpleIdentifierRecursiveAstVisitor(this.visitor);
 
   @override
   visitSimpleIdentifier(SimpleIdentifier node) {
     visitor(node);
   }
 }