This eliminates a lot of stat() calls that happen when lualoader renders the
menu with the default settings, and greatly speeds up rendering on my
laptop.
ftype is nil if loader/loader.efi hasn't been updated yet, falling back to
lfs.attributes() to test.
This is technically incompatible with lfs, but not in a particularly
terrible way.
Reviewed-by: cem
MFC-after: 4 days
Differential Revision: https://reviews.freebsd.org/D27542
e25ee296c9