Check in codegen test expectations.

test/codegen/expect/language/string_intrinsics_test.js

+dart_library.library('language/string_intrinsics_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__string_intrinsics_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 string_intrinsics_test = Object.create(null);
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  let dynamicTodynamic = () => (dynamicTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [dart.dynamic])))();
+  string_intrinsics_test.main = function() {
+    let oneByte = "Hello world";
+    let empty = "";
+    for (let i = 0; i < 20; i++) {
+      expect$.Expect.equals(11, string_intrinsics_test.testLength(oneByte));
+      expect$.Expect.equals(0, string_intrinsics_test.testLength(empty));
+      expect$.Expect.isFalse(string_intrinsics_test.testIsEmpty(oneByte));
+      expect$.Expect.isTrue(string_intrinsics_test.testIsEmpty(empty));
+    }
+  };
+  dart.fn(string_intrinsics_test.main, VoidTodynamic());
+  string_intrinsics_test.testLength = function(s) {
+    return dart.dload(s, 'length');
+  };
+  dart.fn(string_intrinsics_test.testLength, dynamicTodynamic());
+  string_intrinsics_test.testIsEmpty = function(s) {
+    return dart.dload(s, 'isEmpty');
+  };
+  dart.fn(string_intrinsics_test.testIsEmpty, dynamicTodynamic());
+  // Exports:
+  exports.string_intrinsics_test = string_intrinsics_test;
+});