Check in codegen test expectations.

test/codegen/expect/language/issue4515170_test.js

Index: test/codegen/expect/language/issue4515170_test.js
diff --git a/test/codegen/expect/language/issue4515170_test.js b/test/codegen/expect/language/issue4515170_test.js
new file mode 100644
index 0000000000000000000000000000000000000000..4f3cf53c80678edf94013d5508f9be7bae252784
--- /dev/null
+++ b/test/codegen/expect/language/issue4515170_test.js
@@ -0,0 +1,29 @@
+dart_library.library('language/issue4515170_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__issue4515170_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 issue4515170_test = Object.create(null);
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  issue4515170_test.Issue4515170Test = class Issue4515170Test extends core.Object {
+    static defaultVal(a) {
+      if (a === void 0) a = issue4515170_test.Issue4515170Test.VAL;
+      return a;
+    }
+  };
+  dart.setSignature(issue4515170_test.Issue4515170Test, {
+    statics: () => ({defaultVal: dart.definiteFunctionType(core.int, [], [core.int])}),
+    names: ['defaultVal']
+  });
+  issue4515170_test.Issue4515170Test.VAL = 3;
+  issue4515170_test.main = function() {
+    expect$.Expect.equals(3, issue4515170_test.Issue4515170Test.defaultVal());
+  };
+  dart.fn(issue4515170_test.main, VoidTodynamic());
+  // Exports:
+  exports.issue4515170_test = issue4515170_test;
+});