Update errors offsets during incremental comment resolution.

pkg/analyzer/test/generated/incremental_resolver_test.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 engine.incremental_resolver_test;
 
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/error.dart';
@@ skipping 2443 matching lines @@
 class A {}
 ''');
   }
 
   void test_dartDoc_clumsy_updateText_insert() {
     _resolveUnit(r'''
 /**
  * A function [main] with a parameter [p] of type [int].
  */
 main(int p) {
+  unresolvedFunctionProblem();
 }
 /**
  * Other comment with [int] reference.
  */
 foo() {}
 ''');
     _updateAndValidate(r'''
 /**
  * A function [main] with a parameter [p] of type [int].
  * Inserted text with [String] reference.
  */
 main(int p) {
+  unresolvedFunctionProblem();
 }
 /**
  * Other comment with [int] reference.
  */
 foo() {}
 ''');
   }
 
   void test_dartDoc_clumsy_updateText_remove() {
     _resolveUnit(r'''
@@ skipping 914 matching lines @@
   }
 }
 
 
 class _Edit {
   final int offset;
   final int length;
   final String replacement;
   _Edit(this.offset, this.length, this.replacement);
 }