Adds missing V8EXPORT declarations to types in v8-preparser.h.

BUG=
TEST=

Review URL: http://codereview.chromium.org/6812012

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7531 ce2b1a6d-e550-0410-aec6-3dcde31c8c00