Eliminate constructor return types from summaries.

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

 // Copyright (c) 2015, 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 serialization.elements;
 
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/src/dart/element/type.dart';
 import 'package:analyzer/src/generated/resolver.dart';
@@ skipping 375 matching lines @@
     return b;
   }
 
   /**
    * Serialize the given [executableElement], creating an [UnlinkedExecutable].
    */
   UnlinkedExecutableBuilder serializeExecutable(
       ExecutableElement executableElement) {
     UnlinkedExecutableBuilder b = new UnlinkedExecutableBuilder(ctx);
     b.name = executableElement.name;
-    if (!executableElement.type.returnType.isVoid) {
+    if (executableElement is! ConstructorElement &&
+        !executableElement.type.returnType.isVoid) {
       b.returnType = serializeTypeRef(
           executableElement.type.returnType, executableElement);
     }
     b.typeParameters =
         executableElement.typeParameters.map(serializeTypeParam).toList();
     b.parameters =
         executableElement.type.parameters.map(serializeParam).toList();
     if (executableElement is PropertyAccessorElement) {
       if (executableElement.isGetter) {
         b.kind = UnlinkedExecutableKind.getter;
@@ skipping 231 matching lines @@
     UnlinkedVariableBuilder b = new UnlinkedVariableBuilder(ctx);
     b.name = variable.name;
     b.type = serializeTypeRef(variable.type, variable);
     b.isStatic = variable.isStatic && variable.enclosingElement is ClassElement;
     b.isFinal = variable.isFinal;
     b.isConst = variable.isConst;
     b.hasImplicitType = variable.hasImplicitType;
     return b;
   }
 }