Revert two Kernel changes that were causing test failures.

tests/language_2/assertion_initializer_const_function_error_test.dart

-// Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-// VMOptions=--assert_initializer
-//
-// Dart test program testing assert statements.
-
-import "package:expect/expect.dart";
-
-class C {
-  static bool staticTrue() => true;
-  final int x;
-  const C(this.x);
-  // The expression *is* a compile-time constant, but not a bool value.
-  // Static warning, assertion throws which makes it a compile-time error.
-  const C.bc02(this.x, y)
-      : assert(staticTrue) //# 01: static type warning
-      ;
-}
-
-
-main() {
-  // Assertion fails, so in checked mode it's a compile-time error.
-  // Production mode will succeed because the assertion isn't evaluated.
-  var c = const C(1);
-  c = const C.bc02(1, 2);  //# 01: compile-time error
-  if (c.x != 1) throw "non-trivial use of c";
-  Expect.identical(const C(1), c);
-}