Check in codegen test expectations.

test/codegen/expect/corelib/string_to_lower_case_test.js

Index: test/codegen/expect/corelib/string_to_lower_case_test.js
diff --git a/test/codegen/expect/corelib/string_to_lower_case_test.js b/test/codegen/expect/corelib/string_to_lower_case_test.js
new file mode 100644
index 0000000000000000000000000000000000000000..c636e0c8370ed48fe5e6b89646706fec5e314f08
--- /dev/null
+++ b/test/codegen/expect/corelib/string_to_lower_case_test.js
@@ -0,0 +1,28 @@
+dart_library.library('corelib/string_to_lower_case_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__string_to_lower_case_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_to_lower_case_test = Object.create(null);
+  let ListOfint = () => (ListOfint = dart.constFn(core.List$(core.int)))();
+  let intToint = () => (intToint = dart.constFn(dart.definiteFunctionType(core.int, [core.int])))();
+  let intTobool = () => (intTobool = dart.constFn(dart.definiteFunctionType(core.bool, [core.int])))();
+  let VoidTovoid = () => (VoidTovoid = dart.constFn(dart.definiteFunctionType(dart.void, [])))();
+  string_to_lower_case_test.testOneByteSting = function() {
+    let oneByteString = core.String.fromCharCodes(ListOfint().generate(256, dart.fn(i => i, intToint())))[dartx.toLowerCase]();
+    let twoByteString = core.String.fromCharCodes(ListOfint().generate(512, dart.fn(i => i, intToint())))[dartx.toLowerCase]();
+    expect$.Expect.isTrue(twoByteString[dartx.codeUnits][dartx.any](dart.fn(u => dart.notNull(u) >= 256, intTobool())));
+    expect$.Expect.equals(oneByteString, twoByteString[dartx.substring](0, 256));
+  };
+  dart.fn(string_to_lower_case_test.testOneByteSting, VoidTovoid());
+  string_to_lower_case_test.main = function() {
+    string_to_lower_case_test.testOneByteSting();
+  };
+  dart.fn(string_to_lower_case_test.main, VoidTovoid());
+  // Exports:
+  exports.string_to_lower_case_test = string_to_lower_case_test;
+});