These files are part of the SVR4 compatibility options for FreeBSD.

To get SVR4 compat working you will need the system libraries from
Solaris x86.  We cannot supply them to you as a Solaris license is
required in order to use their libraries.

In order to use the SVR4 emulation, simply mount a Solaris 2.5.1 x86 CDROM
on /cdrom.
To make things easier, currently symbolic links are made to the Solaris 
CDROM, thus having it mounted is required when using SVR4 emulation.