Don't attempt to record DynamicElementImpl references.

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

 // Copyright (c) 2016, 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.
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/src/dart/element/member.dart';
@@ skipping 333 matching lines @@
 
   /**
    * Record that [element] has a relation of the given [kind] at the given
    * [offset] and [length].  The flag [isQualified] is `true` if the relation
    * has an explicit or implicit qualifier, so [element] cannot be shadowed by
    * a local declaration.
    */
   void recordRelationOffset(Element element, IndexRelationKind kind, int offset,
       int length, bool isQualified) {
     // Ignore elements that can't be referenced outside of the unit.
-    if (element == null ||
-        element is FunctionElement &&
+    ElementKind elementKind = element?.kind;
+    if (elementKind == null ||
+        elementKind == ElementKind.DYNAMIC ||
+        elementKind == ElementKind.LABEL ||
+        elementKind == ElementKind.LOCAL_VARIABLE ||
+        elementKind == ElementKind.PREFIX ||
+        elementKind == ElementKind.TYPE_PARAMETER ||
+        elementKind == ElementKind.FUNCTION &&
+            element is FunctionElement &&
             element.enclosingElement is ExecutableElement ||
-        element is LabelElement ||
-        element is LocalVariableElement ||
-        element is ParameterElement &&
+        elementKind == ElementKind.PARAMETER &&
+            element is ParameterElement &&
             element.parameterKind != ParameterKind.NAMED ||
-        element is PrefixElement ||
-        element is TypeParameterElement) {
+        false) {
       return;
     }
     // Add the relation.
     assembler.addElementRelation(element, kind, offset, length, isQualified);
   }
 
   /**
    * Record that [element] has a relation of the given [kind] at the location
    * of the given [token].
    */
@@ skipping 419 matching lines @@
         usedNameOffsets: nameRelations.map((r) => r.offset).toList(),
         usedNameIsQualifiedFlags:
             nameRelations.map((r) => r.isQualified).toList());
   }
 
   void defineName(String name, IndexNameKind kind, int offset) {
     _StringInfo nameInfo = pkg._getStringInfo(name);
     definedNames.add(new _DefinedNameInfo(nameInfo, kind, offset));
   }
 }