find(1): Fix -newer and -samefile to conform to POSIX[0]

By default, or with the -P flag, find(1) should evaluate paths "physically."
For symlinks, this means using the link itself instead of the target.

Historically (since the import of BSD 4.4-lite from CSRG), find(1) has
failed to refer to the link itself, at least for -newer and -samefile.

[0]: http://pubs.opengroup.org/onlinepubs/9699919799/utilities/find.html

PR: 222698
Reported by: Harald Schmalzbauer <bugzilla.freebsd AT omnilan.de>
Sponsored by: Dell EMC Isilon