Remove show clauses for types that moved to other libraries.

pkg/analyzer/lib/src/generated/element.dart

Index: pkg/analyzer/lib/src/generated/element.dart
diff --git a/pkg/analyzer/lib/src/generated/element.dart b/pkg/analyzer/lib/src/generated/element.dart
index 6f8d8d2e935bb79c8340b1d49045b7d7df1bbd65..334f4e86e033b891bf4a920da54e7d8e2fd05f50 100644
--- a/pkg/analyzer/lib/src/generated/element.dart
+++ b/pkg/analyzer/lib/src/generated/element.dart
@@ -9,12 +9,11 @@ import 'dart:math' show min;
 
 import 'package:analyzer/src/generated/utilities_general.dart';
 import 'package:analyzer/src/task/dart.dart';
-import 'package:analyzer/task/model.dart'
-    show AnalysisTarget, ConstantEvaluationTarget;
+import 'package:analyzer/task/model.dart' show AnalysisTarget;
 
 import 'ast.dart';
 import 'constant.dart' show DartObject, EvaluationResultImpl;
-import 'engine.dart' show AnalysisContext, AnalysisEngine, AnalysisException;
+import 'engine.dart' show AnalysisContext, AnalysisEngine;
 import 'html.dart' show XmlAttributeNode, XmlTagNode;
 import 'java_core.dart';
 import 'java_engine.dart';