Empty directories

[Gisle Vanem]

I've noted that when build OpenSSL using MSVC,
some empty directories are created:
   ./crypto/include
   ./crypto/providers

I configured with:
   perl.exe -I. -I./util/perl Configure VC-WIN32-ONECORE no-makedepend
   enable-zlib enable-trace enable-md2 no-ec_nistp_64_gcc_128
   enable-asan enable-aria enable-rc5 enable-heartbeats --prefix=/foo/bar
   --openssldir=/foo/bar

I see that the generated Makefile has lots of
'-I "crypto\include"'. AFAICS needlessly. But I
see no 'mkdir crypto\include' anywhere.

And I don't see 'mkdir-p.pl' is used to create these.
So how are these empty directories created/used?

-- 
--gv