Remove $FreeBSD$: one-line .c comment pattern

Remove /^/[*/]\s*\$FreeBSD\$.*\n/

Add different libc ldscript: the one without libssp --
we don't have it when MK_SSP==no.

This fixes compilation on MIPS.

Reviewed by: imp
Sponsored by: DARPA, AFRL
Sponsored by: HEIF5
Differential Revision: https://reviews.freebsd.org/D8212