tests/test-gendoc-zh_TW.t

revlog: use LRU for the chain cache

For a large repository, this reduces the number of filelog instances and
associated data a lot. For a 1% speed penalty, it reduces peak RSS by
20% for the full NetBSD test repository.

Differential Revision: https://phab.mercurial-scm.org/D9235

#require docutils gettext

  $ $TESTDIR/check-gendoc zh_TW
  checking for parse errors