Support for NamedExpression(s) as constructor initializer arguments.

pkg/analyzer/test/src/summary/resynthesize_test.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 test.src.serialization.elements_test;
 
 import 'dart:convert';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/constant/value.dart';
@@ skipping 2458 matching lines @@
     checkLibrary('''
 class A {
   const A.aaa(int p);
 }
 class C extends A {
   const C() : super.aaa(42);
 }
 ''');
   }
 
+  test_constructor_initializers_superInvocation_namedExpression() {
+    checkLibrary('''
+class A {
+  const A.aaa(a, {int b});
+}
+class C extends A {
+  const C() : super.aaa(1, b: 2);
+}
+''');
+  }
+
   test_constructor_initializers_superInvocation_unnamed() {
     checkLibrary('''
 class A {
   const A(int p);
 }
 class C extends A {
   const C.ccc() : super(42);
 }
 ''');
   }
@@ skipping 1886 matching lines @@
       fail('Unexpectedly tried to get unlinked summary for $uri');
     }
     return serializedUnit;
   }
 
   @override
   bool hasLibrarySummary(String uri) {
     return true;
   }
 }