This upgrades the configure infrastructure to the latest Autoconf version.
Some notable news are:
 - The workaround for the broken fseeko() test is gone.
 - Checking for unknown options is now provided by Autoconf itself.
 - Fixes for Mac OS X

Bundle v8.4.0

bundle RC2

time to tag rc1 ...

reportedly is true on OpenBSD.  Also support OpenBSD's spelling of
-Wl,--as-needed.  Per Simon Bertrang.

commit for BETA2

commit and tag beta1

no-op on that platform.

probe for opterr (exactly like the one for optreset) and have getopt.c
define the variables only if configure doesn't find them in libc.

the system's getopt_long().  The previous coding was the result of a sloppy
discussion that failed to draw this distinction.  The result was that PG
programs don't handle options as users of that platform expect.  Per
gripe from Chuck McDevitt.

Although this is a pre-existing bug, I'm not backpatching since I think we
could do with a bit of beta testing before concluding this is really OK.

on AIX with a non-gcc compiler.  The previous coding would do this only if
CC was exactly "xlc"; which is a bad idea, as demonstrated by trouble report
from Mihai Criveti.

way pg_config.h is handled.  This avoids reruns of config.status on every
build, if configure has been rerun.

Also, if linked against other versions than the default MSVCRT library
(for example the MSVC build which links against MSVCRT80), also update
the cache in the default MSVCRT at the same time.

This should fix the issues with setting LC_MESSAGES on the MSVC build.

Original patch from Hiroshi Inoue and Hiroshi Saito, much rewritten
by me.

too).

we can get some buildfarm feedback about whether that function is still
problematic.  (Note that the planned async-preread patch will not really
prove anything one way or the other in buildfarm testing, since it will
be inactive with default GUC settings.)

from Zdenek

various documentation, since those lists are now dead/deprecated.
Point to pgsql-bugs and/or pgsql-hackers as appropriate.

earlier than all the other sizeof checks, and it certainly fails to follow
the order suggested at the file head.  Rearrange.

when --with-system-tzdata is not used.

initial patch by Richard Evans

to the gettext domain name, to simplify parallel installations.

Also, rename set_text_domain() to pg_bindtextdomain(), because that is what
it does.

Plus some makefile cleanup.

part of a patch from Richard Evans

the * character at the beginning of a pattern, and it does not match
subdomains.

Since this means we no longer need fnmatch, remove the imported implementation
from port, along with the autoconf check for it.

page build target.  This covers from-source, Debian, and Fedora
installation variants.

This uses the function fnmatch() which is not available on all platforms
(notably Windows), so import the implementation from NetBSD into src/port.

getpeerucred() function.

Author: Garick Hamlin <ghamlin@isc.upenn.edu>

This basically takes some build system code that was previously labeled
"Solaris" and ties it to the compiler rather than the operating system.

Author: Julius Stroffek <Julius.Stroffek@Sun.COM>

align strings in the --help output.  Do this through our abstraction layer
to eliminate redundancy and randomness in configure.in.

chapter.

Author: Michelle Caisse <Michelle.Caisse@Sun.COM>

change build system to use only Bison.  Simplify build rules, make file names
uniform.  Don't build the token table header file where it is not needed.