Check in codegen test expectations.

test/codegen/expect/language/is_interfaces_test.js

Index: test/codegen/expect/language/is_interfaces_test.js
diff --git a/test/codegen/expect/language/is_interfaces_test.js b/test/codegen/expect/language/is_interfaces_test.js
new file mode 100644
index 0000000000000000000000000000000000000000..a7d1acd6be732f3dd125e39c8170ae2815bf5ce9
--- /dev/null
+++ b/test/codegen/expect/language/is_interfaces_test.js
@@ -0,0 +1,41 @@
+dart_library.library('language/is_interfaces_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__is_interfaces_test(exports, dart_sdk, expect) {
+  'use strict';
+  const core = dart_sdk.core;
+  const _interceptors = dart_sdk._interceptors;
+  const dart = dart_sdk.dart;
+  const dartx = dart_sdk.dartx;
+  const expect$ = expect.expect;
+  const is_interfaces_test = Object.create(null);
+  let JSArrayOfA = () => (JSArrayOfA = dart.constFn(_interceptors.JSArray$(is_interfaces_test.A)))();
+  let intToint = () => (intToint = dart.constFn(dart.definiteFunctionType(core.int, [core.int])))();
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  is_interfaces_test.A = class A extends core.Object {};
+  is_interfaces_test.B = class B extends is_interfaces_test.A {};
+  is_interfaces_test.C = class C extends core.Object {};
+  is_interfaces_test.C[dart.implements] = () => [is_interfaces_test.B];
+  is_interfaces_test.inscrutable = function(x) {
+    return x == 0 ? 0 : (dart.notNull(x) | dart.notNull(is_interfaces_test.inscrutable((dart.notNull(x) & dart.notNull(x) - 1) >>> 0))) >>> 0;
+  };
+  dart.fn(is_interfaces_test.inscrutable, intToint());
+  is_interfaces_test.main = function() {
+    let things = JSArrayOfA().of([new is_interfaces_test.A(), new is_interfaces_test.B(), new is_interfaces_test.C()]);
+    let a = things[dartx.get](is_interfaces_test.inscrutable(0));
+    expect$.Expect.isTrue(is_interfaces_test.A.is(a));
+    expect$.Expect.isFalse(is_interfaces_test.B.is(a));
+    expect$.Expect.isFalse(is_interfaces_test.C.is(a));
+    let b = things[dartx.get](is_interfaces_test.inscrutable(1));
+    expect$.Expect.isTrue(is_interfaces_test.A.is(b));
+    expect$.Expect.isTrue(is_interfaces_test.B.is(b));
+    expect$.Expect.isFalse(is_interfaces_test.C.is(b));
+    let c = things[dartx.get](is_interfaces_test.inscrutable(2));
+    expect$.Expect.isTrue(is_interfaces_test.A.is(c));
+    expect$.Expect.isTrue(is_interfaces_test.B.is(c));
+    expect$.Expect.isTrue(is_interfaces_test.C.is(c));
+  };
+  dart.fn(is_interfaces_test.main, VoidTodynamic());
+  // Exports:
+  exports.is_interfaces_test = is_interfaces_test;
+});