*: Linux emulation: add support for aarch64

PR:		256008
Submitted by:	Vincent Milum Jr (prior version)
Approved by:	emulation (maintainer timeout)

*/*: Remove redundant '-[0-9]*' from CONFLICTS

The conflict checks compare the patterns first against the package
names without version (as reported by "pkg query "%n"), then - if
there was no match - agsinst the full package names including the
version (as reported by "pkg query "%n-%v").

Many CONFLICTS definitions used patterns like "bash-[0-9]*" to filter
for the bash package in any version. But that pattern is functionally
identical with just "bash".

Approved by:	portmgr (blanket)

Remove # $FreeBSD$ from Makefiles.

Update Linux CentOS ports to 7.9.2009.

Update to 1.2.15-15.el7_7.

Address some portlint warnings in the Linux infrastructure ports.

Eliminate LINUXNAME from port Makefiles.  This was just a helper variable
without special meaning outside port Makefiles but several developers have
copied it to new ports where it was then unused, apparently thinking that
it did have some special meaning.

Eliminate RPMVERSION from Linux ports and set DISTVERSIONSUFFIX instead.
This puts all version information together in the port Makefiles.

Add DOCS options to ports that should have one.

Also various fixes related to said option.

PR:		230864
Submitted by:	mat
exp-runs by:	antoine

Enable i386 support to Linux CentOS 7 ports.

PR:		216646

- Autodetect the installed linux_base port and use LINUX_DEFAULT only as
  a last resort.
- Construct a list of DISTFILES for every architecture (amd64, i386).
  Select one list for regular make and all lists for make makesum so linux
  ports can have one combined distinfo file.
- Set DIST_SUBDIR?=centos so there's only one copy of common distfiles.
- Use MASTER_SITES and DISTFILES groups so make fetch is a bit smarter.
- Regenerate all distinfo files.
- For linux_base-c6 (just like linux_base-c7 already does) turn bin, lib,
  lib64 and sbin into symbolic links to the same directory under usr.
  This fixes the problem where some programs/libraries exist under / on
  FreeBSD and /usr on Linux or vice versa and then depending on the order
  of search paths Linux programs may run/load FreeBSD programs/libraries
  and fail.
- Turn usr/share/icons into a symbolic link to LOCALBASE/share/icons so

Update Linux CentOS 7 ports to 7.3.1611.  While 7.2 had semi-official i386
packages there are no such packages for 7.3 yet so i386 support has been
marked IGNORE for now.

Change DIST_SUBDIR to just "centos" so distfiles that remain the same
between major versions don't have to be redownloaded.

Remove fmake hacks from linux.mk.

Submitted by:	Piotr Kubaj <pkubaj@anongoth.pl>

Add Linux CentOS 7 infrastructure ports.

Mk/Uses/linux.mk changes:
- Add support for architecture neutral (noarch) distfiles.
- Add support for 64-bit only ports: set IGNORE on i386 and don't install
  32-bit compat libraries on amd64.

Submitted by:	Piotr Kubaj <pkubaj@anongoth.pl>
Differential Revision:	https://reviews.freebsd.org/D7886