Deprecate the generated AST library and clean up imports

pkg/analyzer/lib/src/summary/summarize_elements.dart

Index: pkg/analyzer/lib/src/summary/summarize_elements.dart
diff --git a/pkg/analyzer/lib/src/summary/summarize_elements.dart b/pkg/analyzer/lib/src/summary/summarize_elements.dart
index 212bb9dfe864fcd418a6816730864adf2897aafb..798c152803e2c79e4438cb33cd94c99d0e1a16e8 100644
--- a/pkg/analyzer/lib/src/summary/summarize_elements.dart
+++ b/pkg/analyzer/lib/src/summary/summarize_elements.dart
@@ -6,12 +6,12 @@ library serialization.elements;
 
 import 'dart:convert';
 
+import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/src/dart/element/element.dart';
 import 'package:analyzer/src/dart/element/member.dart';
 import 'package:analyzer/src/dart/element/type.dart';
-import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/resolver.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/generated/utilities_dart.dart';
@@ -590,7 +590,8 @@ class _CompilationUnitSerializer {
 
   CodeRangeBuilder serializeCodeRange(Element element) {
     if (element is ElementImpl && element.codeOffset != null) {
-      return new CodeRangeBuilder(offset: element.codeOffset, length: element.codeLength);
+      return new CodeRangeBuilder(
+          offset: element.codeOffset, length: element.codeLength);
     }
     return null;
   }