update xetex_version.h

git-svn-id: svn://tug.org/texlive/trunk/Build@34604 c570f23f-e606-0410-a88d-b1316a301751
Fix xetex-bug73.test

git-svn-id: svn://tug.org/texlive/trunk/Build@34618 c570f23f-e606-0410-a88d-b1316a301751
Sync from TeX Live