Remove powerpc left-overs

There since the powerpc -> macppc move/rename.

KERN_AS usage disappeared in
commit 5b7db11d478192c5908038bb1345e7d51cc35c8e
Author: rahnds <rahnds@openbsd.org>
Date: Mon May 5 16:47:15 1997 +0000

only build one version of the libraries.

REAL_VIRT usage disappeared in
commit 08e027d6bb9ca863bfc44a1aa6957ff3a242e2f4
Author: rahnds <rahnds@openbsd.org>
Date: Thu Apr 27 12:36:29 2000 +0000

Fixes to xcoff bootloader to allow it to execute and load kernels for OpenBSD.

Make agrees that these are defined but not used:

$ make -p | grep -e KERN_AS -e REAL_VIRT
KERN_AS = library
REAL_VIRT = -v
$ make -C ofwboot -p | grep -e KERN_AS -e REAL_VIRT
KERN_AS = library
REAL_VIRT = -v

No object change.
Feedback OK miod

Do not create machine@ symlinks in obj as root during includes:, but
defer their creation to later, so that they are owned by BUILDUSER.
This eliminates the last root-owned files in obj/ from 'make build'.
In addition, place a MACHINE == hppa test in hppa/stand/Makefile.inc
to avoid creating bogus symlinks on all other archs.

joint work with & ok natano, "let's try it" deraadt

build the manual pages on all architectures

Add a proper MANSUBDIR, to have manpages install in the proper directory.

Allow bootblocks to build in PIE; joint effort with pascal
boot.mac might still have a problem since it did change size...
looking for a testing report.

avoid builtins completely, so avoid possible issues with gcc4.

few more dribbles of LIBKERN cleanup

Now that errno.h and sys/errno.h are separate header files there is no
need to use the -Derrno=errno workaround added when __errno() was
introduced. OK deraadt@

Remove bogus #define, no binary difference.

errno changes, lib major version bumps, and general flag day
To build you must:
cd /usr/src && make obj && make includes
cd lib/libc && make depend && make && NOMAN=1 sudo make install
cd /usr/src && make build

fix build for gcc3.

Import propolice (http://www.trl.ibm.com/projects/security/ssp), a stack
attack protection scheme, into gcc.

This protection is enabled by default. It can be turned off by using the
-fno-stack-protector flag.

Code by Hiroaki Etoh (etoh at jp dot ibm dot com); work on openbsd-specific
integration by fgsch@, deraadt@ and myself; tests by fgsch@, naddy@ and
myself; beer drinking by myself.

Please note that system upgrades with this new code will require a new
libc and ld.so to be build and installed before the propolice-enabled
compiler can be installed.

branches: 1.2.4; 1.2.6;
Install the bsd.tbxi data file. millert@ ok.

The "powerpc" port which has supported the newer Apple Macintosh powerpc based
is being renamed to macppc. This is to allow sharing of common code
between different powerpc base platforms.

Most of the work involved in the renaming process was performed by miod@

Files moved from powerpc/stand to macppc/stand