win32mbcs: wrap two more functions to be wrapped.
util.checkwinfilename() and util.checkosfilename() are wrapped.
The former, used by scmutil, is not friendly for Shift_JIS bytes.
The latter is an dynamic alias of checkwinfilename() used by other
modules.
$ rm -rf a
$ hg init a
$ cd a
$ echo a > a
$ hg ci -Am0
adding a
$ hg tag t1 # 1
$ hg tag --remove t1 # 2
$ hg co 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg tag -f -r0 t1
$ hg tags
tip 3:a49829c4fc11
t1 0:f7b1eb17ad24