Node::class_id_ contains garbage for newly allocated (FREE) nodes. This patch
changes the code to first test the node state_, then (for non-FREE nodes),
class_id_, and not the other way around.

This does not affect the branch taken (i.e. the current code is correct),
but makes Valgrind and MSan happy.

Review URL: https://codereview.chromium.org/11362158
Patch from Evgeniy Stepanov <eugenis@chromium.org>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12903 ce2b1a6d-e550-0410-aec6-3dcde31c8c00