bug#25360: File mode specification errors during building

[Glenn Morris]

npostavs@users.sourceforge.net wrote:

> Using insert-file-contents instead of file-file-noselect seems to fix it
> for me:

That sounds like a good change anyway. (I forget, does this respect
"coding:"? Does this even matter in this case?)

(But it still seems like a potential problem to me if functions that used to
be available early in the build no longer are.)