Teach analyzer parser to handle native const factories/const constructors.

pkg/analyzer/test/generated/non_error_resolver_test.dart

 // Copyright (c) 2014, 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 analyzer.test.generated.non_error_resolver_test;
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/src/error/codes.dart';
@@ skipping 3709 matching lines @@
 
   void test_nativeFunctionBodyInNonSDKCode_function() {
     Source source = addSource(r'''
 import 'dart-ext:x';
 int m(a) native 'string';''');
     computeLibrarySourceErrors(source);
     assertNoErrors(source);
     // Cannot verify the AST because the import's URI cannot be resolved.
   }
 
+  void test_nativeConstConstructor() {
+    Source source = addSource(r'''
+import 'dart-ext:x';
+class Foo {
+  const Foo() native 'Foo_Foo';
+  const factory Foo.foo() native 'Foo_Foo_foo';
+}''');
+    computeLibrarySourceErrors(source);
+    assertNoErrors(source);
+    // Cannot verify the AST because the import's URI cannot be resolved.
+  }
+
   void test_newWithAbstractClass_factory() {
     Source source = addSource(r'''
 abstract class A {
   factory A() { return new B(); }
 }
 class B implements A {
   B() {}
 }
 A f() {
   return new A();
@@ skipping 2487 matching lines @@
     reset();
   }
 
   void _check_wrongNumberOfParametersForOperator1(String name) {
     _check_wrongNumberOfParametersForOperator(name, "a");
   }
 
   CompilationUnit _getResolvedLibraryUnit(Source source) =>
       analysisContext.getResolvedCompilationUnit2(source, source);
 }