Check in codegen test expectations.

test/codegen/expect/language/left_shift_test.js

+dart_library.library('language/left_shift_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__left_shift_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 left_shift_test = Object.create(null);
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  left_shift_test.main = function() {
+    for (let i = 0; i < 80; i++) {
+      let a = (-1)[dartx['<<']](i);
+      let b = -1;
+      expect$.Expect.equals((1)[dartx['<<']](i), (a / b)[dartx.truncate]());
+    }
+  };
+  dart.fn(left_shift_test.main, VoidTodynamic());
+  // Exports:
+  exports.left_shift_test = left_shift_test;
+});