Fix 23563: double unary- operator unstable for NANs

tests/corelib/nan_infinity_test.dart

 // Copyright (c) 2011, 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.
 
 import "package:expect/expect.dart";
 
 // Dart test program for testing NaN and Infinity.
 
 void main() {
   // Sanity tests.
@@ skipping 36 matching lines @@
   Expect.equals("Infinity", double.INFINITY.toString());
   Expect.equals("-Infinity", double.NEGATIVE_INFINITY.toString());
 
   // Test identities.
   Expect.isTrue(identical(double.NAN, double.NAN));  /// 01: ok
   Expect.isTrue(identical(double.INFINITY, double.INFINITY));
   Expect.isTrue(identical(double.NEGATIVE_INFINITY, double.NEGATIVE_INFINITY));
   Expect.isFalse(identical(double.NAN, double.INFINITY));
   Expect.isFalse(identical(double.NAN, double.NEGATIVE_INFINITY));
   Expect.isFalse(identical(double.INFINITY, double.NEGATIVE_INFINITY));
-  Expect.isTrue(identical(double.NAN, -double.NAN));  /// 01: continued
+  Expect.isFalse(identical(double.NAN, -double.NAN));
   Expect.isTrue(identical(double.INFINITY, -double.NEGATIVE_INFINITY));
   Expect.isTrue(identical(double.NEGATIVE_INFINITY, -double.INFINITY));
 
   // Test equalities
   Expect.isTrue(double.INFINITY == double.INFINITY);
   Expect.isTrue(double.NEGATIVE_INFINITY == double.NEGATIVE_INFINITY);
   Expect.isFalse(double.INFINITY == double.NEGATIVE_INFINITY);
   Expect.isFalse(double.NEGATIVE_INFINITY == double.INFINITY);
   Expect.isFalse(double.NAN == double.NAN);
   Expect.isFalse(double.NAN == double.INFINITY);
@@ skipping 13 matching lines @@
   Expect.isFalse(double.INFINITY > double.NAN);
   Expect.isFalse(double.NEGATIVE_INFINITY > double.NAN);
   Expect.isTrue(double.INFINITY > double.NEGATIVE_INFINITY);
   Expect.isFalse(double.INFINITY < double.NEGATIVE_INFINITY);
 
   // NaN is contagious.
   Expect.isTrue((3.0 * double.NAN).isNaN);
   Expect.isTrue((3.0 + double.NAN).isNaN);
   Expect.isTrue((-double.NAN).isNaN);
 }