Break up another large file

pkg/analyzer/lib/src/dart/sdk/sdk.dart

Index: pkg/analyzer/lib/src/dart/sdk/sdk.dart
diff --git a/pkg/analyzer/lib/src/dart/sdk/sdk.dart b/pkg/analyzer/lib/src/dart/sdk/sdk.dart
index 675ce9b55f29af380f8326075c510051697fbe37..0123bf8c1758f1a43514ee10cccb52cbba9f972e 100644
--- a/pkg/analyzer/lib/src/dart/sdk/sdk.dart
+++ b/pkg/analyzer/lib/src/dart/sdk/sdk.dart
@@ -9,6 +9,7 @@ import 'dart:convert';
 import 'dart:io' as io;
 
 import 'package:analyzer/dart/ast/ast.dart';
+import 'package:analyzer/error/listener.dart';
 import 'package:analyzer/exception/exception.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/file_system/memory_file_system.dart';
@@ -16,7 +17,6 @@ import 'package:analyzer/src/context/context.dart';
 import 'package:analyzer/src/dart/scanner/reader.dart';
 import 'package:analyzer/src/dart/scanner/scanner.dart';
 import 'package:analyzer/src/generated/engine.dart';
-import 'package:analyzer/src/generated/error.dart';
 import 'package:analyzer/src/generated/java_engine_io.dart';
 import 'package:analyzer/src/generated/parser.dart';
 import 'package:analyzer/src/generated/sdk.dart';