Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

- Removing some unneeded definitions of NULL(cruft related to 1970's C).
In C90, NULL is guaranteed to be declared in <stddef.h> and also in
<string.h>. Though the correct way to define NULL in FreeBSD is to
include <sys/_null.h>, other parts of libstand still require <string.h>
to build; therefore, we keep <string.h> in stand.h and add a note about
this;
- Removing no longer used 'Prototype' definition. Quote from bde@:

'Cruft related to getting incomplete struct declarations within
prototypes forward-declared before the structs. It doesn't mean
"prototype" but only part of a prototype-related hack. No longer
used.'

- Replacing iaddr_t with uintptr_t;
- Removing use of long double to determine alignment. Use a fixed 16 byte
alignment instead;

Reviewed by: bde
Obtained from: DragonFlyBSD (partially)
MFC after: 1 month

Using the correct format string(%zu) for size_t type. This should fix 64
bits builds.

Submitted by: Garrett Cooper <yanegomi@gmail.com>

Eliminate __alpha__ leftover from libstand.

Use signed char cast to avoid out-of-range error on PowerPC (which has
unsigned char by default). This is a no-op on all other current arches.

Tested by: md5 sum before/after same on i386

- Print out line number in a panic message using %d rather than %p. Line
numbers aren't pointers.
- Add a __printflike() attribute to libstand's panic() prototype to catch
such bogons in the future.

Reimplement malloc/free debugging that includes the offending file:line
info. This turned out to be rather useful on ia64 for tracking down
malloc/free problems.
Detect duplicate free()'s - otherwise these show up as a guard1 failure
and it looks like corruption instead of something simple like a second
free() where there shouldn't be.
Deal with libz using libc headers and not seeing the malloc/free stuff that
we provide in libstand. Do similar nastiness to what is done for bzlib.

Tested on: i386, ia64 (compile, run)

Add __FBSDID()s to libstand

$Id$ -> $FreeBSD$

Implement a hook to allow us to reclaim the memory used by the first stage
of the bootstrap (the bit which loads /boot/loader).

Prune unused zalloc components as recommended by Matt Dillon. Extra debugging
code is still enabled (it's not very expensive).

* Enable old UFS compatibility code for booting from Digital Unix formatted
disks.
* Fix a whole raft of warnings, printf and otherwise.
* Make zalloc work for alpha (just a case of using the right typedef).
* Add some (disabled) malloc debug printing to stand.h.

Replace the old and extremely icky Mach/NetBSD allocator with a similarly
compact and much better one donated by Matt Dillon. Implement a simple
sbrk() which uses the existing setheap() api.

Remove the custom allocator from the UFS code. It wasn't working quite
right, and it shouldn't be needed with the new allocator.

Fix a serious problem with changing the value of already-existent
environment variables. Don't attempt to modify the supposedly-const
argument to putenv()

Fix an off-by-one sizing error in the zipfs code detected by the new
allocator.

Submitted by: zmalloc from Matt Dillon <dillon@backplane.com>