Re-create wildignore options file if missing
Re-create wildignore options file if missing

When the wildignore options file is a temp file it can be deleted by
other processes which clean up temp files, so check the file is readable
and re-create if necessary before adding it to the list of files from
which to read exclusion patterns (-x option for update_tags scripts).

Without this Gutentags sometimes gets stuck in a rut reporting ctags job
failed, probably because I use both GUI vim and terminal vim, but might
not use the GUI for days and when I return to it the temp file is gone.

ludovicchabant/vim-gutentags