Log Message:
Kill Interix libc shlibname base OS_VERSION detection, broken for SUA.

It is based on ancient bsd.prefs.mk and not works as expected for SUA,
because all SUA (5.2, 6.0 and 6.1) have libc.so.5.2 (and also old version).
Moreover shlibname base OS version was introduced to speed up to avoid invoking
`uname', but in this script, `uname' always will be invoked.