dart2js js_runtime: faster code for floor() & ceil()

tests/corelib/double_floor_test.dart

Index: tests/corelib/double_floor_test.dart
diff --git a/tests/corelib/double_floor_test.dart b/tests/corelib/double_floor_test.dart
index c59f411351a111ba7d326f0dc30ddc5418954197..7407561bf67b27ad9d4899c3e94097cfec4a66ff 100644
--- a/tests/corelib/double_floor_test.dart
+++ b/tests/corelib/double_floor_test.dart
@@ -79,4 +79,4 @@ main() {
   Expect.isTrue((-9007199254740991.0).floor() is int);
   Expect.isTrue((-9007199254740992.0).floor() is int);
   Expect.isTrue((-double.MAX_FINITE).floor() is int);
-}
+}