autoloading from deleted wordcode digest files

[Clint Adams <schizo@xxxxxxxxxx>]

I'm making .zwc files using zcompile -U -M.
zsh will keep these files opened and mmapped even
after they are deleted, but efforts to autoload
functions within will fail.

I want the deleted file to be searched if the function
is not found on disk.  I assume that this can be accomplished
by including the filename in struct funcdump, and using
that as an identifier should the files be deleted after
mmapping.

Will this break anything?