Check in codegen test expectations.

test/codegen/expect/corelib/reg_exp_first_match_test.js

Index: test/codegen/expect/corelib/reg_exp_first_match_test.js
diff --git a/test/codegen/expect/corelib/reg_exp_first_match_test.js b/test/codegen/expect/corelib/reg_exp_first_match_test.js
new file mode 100644
index 0000000000000000000000000000000000000000..fa4a1cf71913834e4ab870ac3f70f25e4e9cd4c6
--- /dev/null
+++ b/test/codegen/expect/corelib/reg_exp_first_match_test.js
@@ -0,0 +1,28 @@
+dart_library.library('corelib/reg_exp_first_match_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__reg_exp_first_match_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 reg_exp_first_match_test = Object.create(null);
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  reg_exp_first_match_test.RegExpFirstMatchTest = class RegExpFirstMatchTest extends core.Object {
+    static testMain() {
+      expect$.Expect.equals('cat', core.RegExp.new("(\\w+)").firstMatch("cat dog").get(0));
+      expect$.Expect.equals(null, core.RegExp.new("foo").firstMatch("bar"));
+    }
+  };
+  dart.setSignature(reg_exp_first_match_test.RegExpFirstMatchTest, {
+    statics: () => ({testMain: dart.definiteFunctionType(dart.dynamic, [])}),
+    names: ['testMain']
+  });
+  reg_exp_first_match_test.main = function() {
+    reg_exp_first_match_test.RegExpFirstMatchTest.testMain();
+  };
+  dart.fn(reg_exp_first_match_test.main, VoidTodynamic());
+  // Exports:
+  exports.reg_exp_first_match_test = reg_exp_first_match_test;
+});