libc: remove some obsolete VCS data

These wide char support files were copied from the previous versions
with expanded $FreeBSD$ strings in #if 0 blocks. Remove them and the
scssid definitions in the same #if 0 blocks.

Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D42688

(cherry picked from commit 9fc0ff9d85b1497b45a4c6d74e0bc7eea9dcf37b)