'RELENG_7_0_0_RELEASE'.

This commit was manufactured to restore the state of the 7.0-RELEASE image.

clause.

# If I've done so improperly on a file, please let me know.

Obtained from:	NetBSD
MFC after:	1 week

Spotted by:	bde

re-read from the stack mid copy.  This may help mitigate the recent
Apache buffer overrun and future overruns of the sort.

Reviewed by:	jdp
MFC after:	2 days

- use a slightly less bogus copyright.  This file was never contributed
  to Berkeley.  It still claims to be copright by the Regents.
- use <machine/asm.h> instead of "DEFS.h".
- use RCSID($Id$) instead of explicit assembly code and messy ifdefs.
  The rcsid won't be put into the object file until we make RCSID()
  non-null.  NetBSD uses a LIBC_SCCS ifdef here.  We used a LIBC_RCS
  instead, but I want RCSID() to be controlled directly by LIBC_RCS
  (actually by LIB_RCS).  This is the only difference with the NetBSD
  version.
- added ifdefs to support generation of memcpy() and memmove().  The
  other changes are "while I'm here" to get this.
- improved style of the copy backwards case.

This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore.  This update would have been
insane otherwise.

is really necessary. Going backwards on a P6 is much slower than forwards
and it's a little slower on a P5. Also moved the count mask and 'std'
down a few lines - it's a couple percent faster this way on a P5.