ceil/floor/truncate/round return integers.

pkg/fixnum/test/int_64_vm_test.dart

 // Copyright (c) 2012, 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.
 
 // A test to compare the results of the fixnum library with the Dart VM
 
 library int64vmtest;
 import 'dart:math' as math;
 
 part '../lib/src/int32.dart';
@@ skipping 38 matching lines @@
       i = (i << 1) | ((rand > 0.5) ? 1 : 0);
   }
   return new int64.fromInt(i);
 }
 
 int _randomInt(int n) {
   double rand = random.nextDouble();
   for (int i = 0; i < DISCARD; i++) {
     rand = random.nextDouble();
   }
-  return (rand * n).floor().toInt();
+  return (rand * n).floor();
 }
 
 class Op {
   String name;
   Function op;
 
   Op(String this.name, Function this.op);
 
   // Truncate x to a value in the range [-2^63, 2^63 - 1]
   int trunc64(int x) {
@@ skipping 250 matching lines @@
       }
     }
     for (int i = 0; i < RANDOM_TESTS; i++) {
       int64 randomLong = _randomInt64();
       for (int shift = -64; shift <= 64; shift++) {
         _doTestShift(op, randomLong, shift);
       }
     }
   }
 }