Copy stable/11@r303970 to releng/11.0 as part of the 11.0-RELEASE
cycle.

Prune svn:mergeinfo from the new branch, and rename it to RC1.

Update __FreeBSD_version.

Use the quarterly branch for the default FreeBSD.conf pkg(8) repo and
the dvd1.iso packages population.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

libc: do not include <sys/types.h> where <sys/param.h> was already included

According to style(9):
> normally, include <sys/types.h> OR <sys/param.h>, but not both.
(<sys/param.h> already includes <sys/types.h> when LOCORE is not defined).

libc: don't build compat functions if building WITHOUT_SYMVER

WITHOUT_SYMVER necessarily implies building a system without symver
backwards compatability.

Sponsored by: The FreeBSD Foundation

Remove a stale comment and clarify the original where it was taken from

The comment in the libc/sys symbol map referenced the generated symbols
for the syscall trampolines. Such comment was out of place in the secure
symbol map so remove the stale comment and attempt to clarify the old one
to avoid risks of confusion.

Pointed out by: kib

Move the stack protector to a new "secure" directory

As part of the code refactoring to support FORTIFY_SOURCE we want
a new subdirectory "secure" to keep the files related to security.
Move the stack protector functions to this new directory.

No functional change.

Differential Review: https://reviews.freebsd.org/D3333