Initialize Date parse cache with SMI instead of double to workaround sharing...

Initialize Date parse cache with SMI instead of double to workaround sharing mutable heap numbers in snapshot.

This is the only field in the snapshot that was tracked as double.

R=verwaest@chromium.org
TEST=mjsunit/regress/regress-280531.js
BUG=280531
LOG=Y

Review URL: https://chromiumcodereview.appspot.com/112003005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@18298 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/date.js

@@ -132,7 +132,7 @@ function TimeClip(time) {
 // strings over and over again.
 var Date_cache = {
   // Cached time value.
-  time: NAN,
+  time: 0,
   // String input for which the cached time is valid.
   string: null
 };

test/mjsunit/regress/regress-280531.js

+// Copyright 2013 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+var contextA = Realm.create();
+var date1 = Realm.eval(contextA, "new Date('Thu, 29 Aug 2013 00:00:00 UTC')");
+new Date('Thu, 29 Aug 2013 00:00:01 UTC');
+var date2 = Realm.eval(contextA, "new Date('Thu, 29 Aug 2013 00:00:00 UTC')");
+assertEquals(date1, date2);