Check in codegen test expectations.

test/codegen/expect/language/issue13673_test.js

Index: test/codegen/expect/language/issue13673_test.js
diff --git a/test/codegen/expect/language/issue13673_test.js b/test/codegen/expect/language/issue13673_test.js
new file mode 100644
index 0000000000000000000000000000000000000000..76ab8d0dc390d0bf9ee9dbc88c258c92d1be0623
--- /dev/null
+++ b/test/codegen/expect/language/issue13673_test.js
@@ -0,0 +1,36 @@
+dart_library.library('language/issue13673_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__issue13673_test(exports, dart_sdk, expect) {
+  'use strict';
+  const core = dart_sdk.core;
+  const dart = dart_sdk.dart;
+  const dartx = dart_sdk.dartx;
+  const expect$ = expect.expect;
+  const issue13673_test = Object.create(null);
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  issue13673_test.Bar = class Bar extends core.Object {
+    new(field) {
+      this.field = field;
+    }
+    foo() {
+      return this.field;
+    }
+  };
+  dart.setSignature(issue13673_test.Bar, {
+    constructors: () => ({new: dart.definiteFunctionType(issue13673_test.Bar, [core.Type])}),
+    methods: () => ({foo: dart.definiteFunctionType(dart.dynamic, [])})
+  });
+  dart.defineLazy(issue13673_test, {
+    get topLevel() {
+      return new issue13673_test.Bar(dart.wrapType(core.String)).foo();
+    },
+    set topLevel(_) {}
+  });
+  issue13673_test.main = function() {
+    expect$.Expect.isTrue(core.Type.is(issue13673_test.topLevel));
+  };
+  dart.fn(issue13673_test.main, VoidTodynamic());
+  // Exports:
+  exports.issue13673_test = issue13673_test;
+});