Make snapshots reproducible.

Make snapshots reproducible.

To keep the structure of the serializer more or less untouched, we use
some ingenious Corry-approved(TM) 3-step technology (a.k.a. "hack"):

   * Create copies of code objects.
   * Wipe out all absolute addresses in these copies.
   * Write out the cleaned copies instead of the originals.

In conjunction with --random-seed, our snapshots are reproducible now.

BUG=v8:2885
R=bmeurer@chromium.org, erik.corry@gmail.com

Review URL: https://codereview.chromium.org/54823002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17473 ce2b1a6d-e550-0410-aec6-3dcde31c8c00