Check in codegen test expectations.

test/codegen/expect/language/mixin_super_constructor_multiple_test.js

+dart_library.library('language/mixin_super_constructor_multiple_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__mixin_super_constructor_multiple_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 mixin_super_constructor_multiple_test = Object.create(null);
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  mixin_super_constructor_multiple_test.S = class S extends core.Object {
+    foo() {
+      this.i = 1742;
+    }
+  };
+  dart.defineNamedConstructor(mixin_super_constructor_multiple_test.S, 'foo');
+  dart.setSignature(mixin_super_constructor_multiple_test.S, {
+    constructors: () => ({foo: dart.definiteFunctionType(mixin_super_constructor_multiple_test.S, [])})
+  });
+  mixin_super_constructor_multiple_test.M1 = class M1 extends core.Object {};
+  mixin_super_constructor_multiple_test.M2 = class M2 extends core.Object {};
+  mixin_super_constructor_multiple_test.C = class C extends dart.mixin(mixin_super_constructor_multiple_test.S, mixin_super_constructor_multiple_test.M1, mixin_super_constructor_multiple_test.M2) {
+    foo() {
+      super.foo();
+    }
+  };
+  dart.defineNamedConstructor(mixin_super_constructor_multiple_test.C, 'foo');
+  dart.setSignature(mixin_super_constructor_multiple_test.C, {
+    constructors: () => ({foo: dart.definiteFunctionType(mixin_super_constructor_multiple_test.C, [])})
+  });
+  mixin_super_constructor_multiple_test.main = function() {
+    expect$.Expect.equals(1742, new mixin_super_constructor_multiple_test.C.foo().i);
+  };
+  dart.fn(mixin_super_constructor_multiple_test.main, VoidTodynamic());
+  // Exports:
+  exports.mixin_super_constructor_multiple_test = mixin_super_constructor_multiple_test;
+});