Check in codegen test expectations.

test/codegen/expect/corelib/regress_r21715_test.js

+dart_library.library('corelib/regress_r21715_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__regress_r21715_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 regress_r21715_test = Object.create(null);
+  let dynamicAnddynamicTodynamic = () => (dynamicAnddynamicTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [dart.dynamic, dart.dynamic])))();
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  regress_r21715_test.sll = function(x, shift) {
+    return dart.dsend(x, '<<', shift);
+  };
+  dart.fn(regress_r21715_test.sll, dynamicAnddynamicTodynamic());
+  regress_r21715_test.main = function() {
+    for (let i = 0; i < 10; i++) {
+      let x = 1342177280;
+      let shift = 34;
+      expect$.Expect.equals(regress_r21715_test.sll(x, shift), 23058430092136939520);
+    }
+  };
+  dart.fn(regress_r21715_test.main, VoidTodynamic());
+  // Exports:
+  exports.regress_r21715_test = regress_r21715_test;
+});