Fixed a bug in isNegate intrinsified code, fixed negation for doubles (handling of negative zeros...

tests/language/src/ArithmeticTest.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.
 // Dart test program to test arithmetic operations.
 
 class ArithmeticTest {
 
   static bool exceptionCaughtParseInt(String s) {
     try {
       Math.parseInt(s);
@@ skipping 119 matching lines @@
     // Big.
     Expect.equals(false, big.isNegative());
     Expect.equals(true, (-big).isNegative());
     // Double.
     // TODO(srdjan): enable the following test once isNegative works.
     // Expect.equals(true, (-0.0).isNegative());
     Expect.equals(false, (0.0).isNegative());
     Expect.equals(false, (2.0).isNegative());
     Expect.equals(true, (-2.0).isNegative());
 
+    double negateDouble(double x) {
+      return -x;
+    }
+
+    Expect.isTrue(negateDouble(0.0).isNegative());
+    Expect.isFalse(negateDouble(-0.0).isNegative());
+    Expect.isTrue(negateDouble(3.5e3).isNegative());
+    Expect.isFalse(negateDouble(-3.5e3).isNegative());
+    
+
     // Constants.
     final nan = 0.0/0.0;
     final infinity = 1.0/0.0;
 
     // -- isInfinite --.
     // Smi.
     Expect.equals(false, (0).isInfinite());
     Expect.equals(false, (1).isInfinite());
     Expect.equals(false, (-1).isInfinite());
     // Big.
@@ skipping 248 matching lines @@
   static testMain() {
     for (int i = 0; i < 1500; i++) {
       runOne();
     }
   }
 }
 
 main() {
   ArithmeticTest.testMain();
 }