zsh_completion: complete hg files

Differential Revision: https://phab.mercurial-scm.org/D4361

contrib/zsh_completion

@@ -631,6 +631,13 b' typeset -A _hg_cmd_globals'
   '*:revision:_hg_labels'
 }
 
+_hg_cmd_files() {
+  _arguments -s -S : $_hg_global_opts $_hg_pat_opts $_hg_subrepos_opts \
+  '(--rev -r)'{-r+,--rev=}'[search the repository as it is in REV]:revision:_hg_labels' \
+  '(--print0 -0)'{-0,--print0}'[end filenames with NUL, for use with xargs]' \
+  '*:file:_hg_files'
+}
+
 _hg_cmd_forget() {
   _arguments -s -S : $_hg_global_opts $_hg_pat_opts $_hg_dryrun_opts \
   '(--interactive -i)'{-i,--interactive}'[use interactive mode]' \