Check in codegen test expectations.

test/codegen/expect/corelib/double_floor2_test.js

+dart_library.library('corelib/double_floor2_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__double_floor2_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 double_floor2_test = Object.create(null);
+  let VoidToint = () => (VoidToint = dart.constFn(dart.definiteFunctionType(core.int, [])))();
+  let dynamicTobool = () => (dynamicTobool = dart.constFn(dart.definiteFunctionType(core.bool, [dart.dynamic])))();
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  double_floor2_test.main = function() {
+    expect$.Expect.throws(dart.fn(() => core.double.INFINITY[dartx.floor](), VoidToint()), dart.fn(e => core.UnsupportedError.is(e), dynamicTobool()));
+    expect$.Expect.throws(dart.fn(() => core.double.NEGATIVE_INFINITY[dartx.floor](), VoidToint()), dart.fn(e => core.UnsupportedError.is(e), dynamicTobool()));
+    expect$.Expect.throws(dart.fn(() => core.double.NAN[dartx.floor](), VoidToint()), dart.fn(e => core.UnsupportedError.is(e), dynamicTobool()));
+  };
+  dart.fn(double_floor2_test.main, VoidTodynamic());
+  // Exports:
+  exports.double_floor2_test = double_floor2_test;
+});