allow rounding errors on a couple arithmetic tests

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 304 matching lines @@
     { double d = (1).toDouble(); }
     { double d = (-1).toDouble(); }
     // Big.
     Expect.equals(big, big.toInt());
     Expect.equals(-big, (-big).toInt());
     { int i = big.toInt(); }
     { int i = (-big).toInt(); }
 
     // Math functions.
     Expect.equals(2.0, Math.sqrt(4.0));
-    Expect.equals(1.0, Math.sin(3.14159265 / 2.0));
-    Expect.equals(-1.0, Math.cos(3.14159265));
+    Expect.approxEquals(1.0, Math.sin(3.14159265 / 2.0));
+    Expect.approxEquals(-1.0, Math.cos(3.14159265));
 
     Expect.equals(12, Math.parseInt("12"));
     Expect.equals(-12, Math.parseInt("-12"));
     Expect.equals(12345678901234567890,
                   Math.parseInt("12345678901234567890"));
     Expect.equals(-12345678901234567890,
                   Math.parseInt("-12345678901234567890"));
     // Type checks.
     { int i = Math.parseInt("12"); }
     { int i = Math.parseInt("-12"); }
@@ skipping 49 matching lines @@
     Expect.equals(false, (3.4).hashCode() == (1.2).hashCode());
     Expect.equals(true, (1.2).hashCode() == (1.2).hashCode());
     Expect.equals(false, (3).hashCode() == (1).hashCode());
     Expect.equals(true, (10).hashCode() == (10).hashCode());
   }
 }
 
 main() {
   ArithmeticTest.testMain();
 }