'RELENG_6_0_0_RELEASE'.

This commit was manufactured to restore the state of the 6.0-RELEASE image.

place.

This moves the dependency on GCC's and other compiler's features into
the central sys/cdefs.h file, while the individual source files can
then refer to #ifdef __COMPILER_FEATURE_FOO where they by now used to
refer to #if __GNUC__ > 3.1415 && __BARC__ <= 42.

By now, GCC and ICC (the Intel compiler) have been actively tested on
IA32 platforms by netchild.  Extension to other compilers is supposed
to be possible, of course.

Submitted by:	netchild
Reviewed by:	various developers on arch@, some time ago

license, per letter dated July 22, 1999 and email from Peter Wemm,
Alan Cox and Robert Watson.

Approved by: core, peter, alc, rwatson

case.

  called <machine/_types.h>.
o <machine/ansi.h> will continue to live so it can define MD clock
  macros, which are only MD because of gratuitous differences between
  architectures.
o Change all headers to make use of this.  This mainly involves
  changing:
    #ifdef _BSD_FOO_T_
    typedef	_BSD_FOO_T_	foo_t;
    #undef _BSD_FOO_T_
    #endif
  to:
    #ifndef _FOO_T_DECLARED
    typedef	__foo_t	foo_t;
    #define	_FOO_T_DECLARED
    #endif

Concept by:	bde
Reviewed by:	jake, obrien

_BYTE_ORDER.  These are far more useful than their non-underscored
equivalents as these can be used in restricted namespace environments.
Mark the non-underscored variants as deprecated.

o In i386's <machine/endian.h>, macros have some advantages over
  inlines, so change some inlines to macros.
o In i386's <machine/endian.h>, ungarbage collect word_swap_int()
  (previously __uint16_swap_uint32), it has some uses on i386's with
  PDP endianness.

Submitted by:	bde

o Move a comment up in <machine/endian.h> that was accidentially moved
  down a few revisions ago.
o Reenable userland's use of optimized inline-asm versions of
  byteorder(3) functions.
o Fix ordering of prototypes vs. redefinition of byteorder(3)
  functions, so that the non-GCC (libc asm) case has proper
  prototypes.
o Add proper prototypes for byteorder(3) functions in <sys/param.h>.
o Prevent redundant duplicate prototypes by making use of the
  _BYTEORDER_PROTOTYPED define.
o Move the bswap16(), bswap32(), bswap64() C functions into MD space
  for platforms in which asm versions don't exist.  This significantly
  reduces the complexity of some things at the cost of duplicate code.

Reviewed by:	bde

device drivers for bus system with other endinesses than the CPU (using
interfaces compatible to NetBSD):

- bwap16() and bswap32(). These have optimized implementations on some
  architectures; for those that don't, there exist generic implementations.
- macros to convert from a certain byte order to host byte order and vice
  versa, using a naming scheme like le16toh(), htole16().
  These are implemented using the bswap functions.
- stream bus space access functions, which do not perform a byte order
  conversion (while the normal access functions would if the bus endianess
  differs from the CPU endianess).

htons(), htonl(), ntohs() and ntohl() are implemented using the new
functions above for kernel usage. None of the above interfaces is currently
exported to user land.

Make use of the new functions in a few places where local implementations
of the same functionality existed.

Reviewed by:	mike, bde
Tested on alpha by:	mike