chore: Rerun ./autogen.sh --maintainer and update .gitignore

Bring the auto-generated scripts up to date with the autoconf upgrade
from version 2.71 to version 2.72.

Make the .gitignore exclusions better tailored to the autoconf- and
configure-generated artifacts.

Author: ctruta

.gitignore

@@ -39,28 +39,29 @@
 *.su
 
 # Libpng configuration and build artifacts
+*.out
 .deps/
 .dirstamp
-Makefile
-autom4te.cache/
-config.h
-config.h.in~
-config.log
-config.status
-configure~
-libpng-config
-libpng.pc
-libpng.vers
-libpng16-config
-libpng16.pc
-libtool
+/Makefile
+/autom4te.cache/
+/config.guess~
+/config.h.in~
+/config.log
+/config.status
+/config.sub~
+/configure~
+/install-sh~
+/libpng-config
+/libpng.pc
+/libpng.vers
+/libpng16-config
+/libpng16.pc
+/libtool
+/stamp-h1
 pnglibconf.[ch]
 pnglibconf.dfn
-pnglibconf.out
 pnglibconf.pre
 pngprefix.h
-stamp-h1
-vers.out
 
 # Libpng test artifacts
 png-fix-itxt

aclocal.m4

@@ -14,8 +14,8 @@
 m4_ifndef([AC_CONFIG_MACRO_DIRS], [m4_defun([_AM_CONFIG_MACRO_DIRS], [])m4_defun([AC_CONFIG_MACRO_DIRS], [_AM_CONFIG_MACRO_DIRS($@)])])
 m4_ifndef([AC_AUTOCONF_VERSION],
   [m4_copy([m4_PACKAGE_VERSION], [AC_AUTOCONF_VERSION])])dnl
-m4_if(m4_defn([AC_AUTOCONF_VERSION]), [2.71],,
-[m4_warning([this file was generated for autoconf 2.71.
+m4_if(m4_defn([AC_AUTOCONF_VERSION]), [2.72],,
+[m4_warning([this file was generated for autoconf 2.72.
 You have another version of autoconf.  It may work, but is not guaranteed to.
 If you have problems, you may need to regenerate the build system entirely.
 To do so, use the procedure documented by the package, typically 'autoreconf'.])])

config.guess

@@ -1,14 +1,14 @@
 #! /bin/sh
 # Attempt to guess a canonical system name.
-#   Copyright 1992-2021 Free Software Foundation, Inc.
+#   Copyright 1992-2023 Free Software Foundation, Inc.
 
 # shellcheck disable=SC2006,SC2268 # see below for rationale
 
-timestamp='2021-06-03'
+timestamp='2023-08-22'
 
 # This file is free software; you can redistribute it and/or modify it
 # under the terms of the GNU General Public License as published by
-# the Free Software Foundation; either version 3 of the License, or
+# the Free Software Foundation, either version 3 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful, but
@@ -47,7 +47,7 @@ me=`echo "$0" | sed -e 's,.*/,,'`
 usage="\
 Usage: $0 [OPTION]
 
-Output the configuration name of the system \`$me' is run on.
+Output the configuration name of the system '$me' is run on.
 
 Options:
   -h, --help         print this help, then exit
@@ -60,13 +60,13 @@ version="\
 GNU config.guess ($timestamp)
 
 Originally written by Per Bothner.
-Copyright 1992-2021 Free Software Foundation, Inc.
+Copyright 1992-2023 Free Software Foundation, Inc.
 
 This is free software; see the source for copying conditions.  There is NO
 warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE."
 
 help="
-Try \`$me --help' for more information."
+Try '$me --help' for more information."
 
 # Parse command line
 while test $# -gt 0 ; do
@@ -102,8 +102,8 @@ GUESS=
 # temporary files to be created and, as you can see below, it is a
 # headache to deal with in a portable fashion.
 
-# Historically, `CC_FOR_BUILD' used to be named `HOST_CC'. We still
-# use `HOST_CC' if defined, but it is deprecated.
+# Historically, 'CC_FOR_BUILD' used to be named 'HOST_CC'. We still
+# use 'HOST_CC' if defined, but it is deprecated.
 
 # Portable tmp directory creation inspired by the Autoconf team.
 
@@ -155,6 +155,9 @@ Linux|GNU|GNU/*)
 
 	set_cc_for_build
 	cat <<-EOF > "$dummy.c"
+	#if defined(__ANDROID__)
+	LIBC=android
+	#else
 	#include <features.h>
 	#if defined(__UCLIBC__)
 	LIBC=uclibc
@@ -169,6 +172,7 @@ Linux|GNU|GNU/*)
 	LIBC=musl
 	#endif
 	#endif
+	#endif
 	EOF
 	cc_set_libc=`$CC_FOR_BUILD -E "$dummy.c" 2>/dev/null | grep '^LIBC' | sed 's, ,,g'`
 	eval "$cc_set_libc"
@@ -437,7 +441,7 @@ case $UNAME_MACHINE:$UNAME_SYSTEM:$UNAME_RELEASE:$UNAME_VERSION in
 	# This test works for both compilers.
 	if test "$CC_FOR_BUILD" != no_compiler_found; then
 	    if (echo '#ifdef __amd64'; echo IS_64BIT_ARCH; echo '#endif') | \
-		(CCOPTS="" $CC_FOR_BUILD -E - 2>/dev/null) | \
+		(CCOPTS="" $CC_FOR_BUILD -m64 -E - 2>/dev/null) | \
 		grep IS_64BIT_ARCH >/dev/null
 	    then
 		SUN_ARCH=x86_64
@@ -459,7 +463,7 @@ case $UNAME_MACHINE:$UNAME_SYSTEM:$UNAME_RELEASE:$UNAME_VERSION in
 		UNAME_RELEASE=`uname -v`
 		;;
 	esac
-	# Japanese Language versions have a version number like `4.1.3-JL'.
+	# Japanese Language versions have a version number like '4.1.3-JL'.
 	SUN_REL=`echo "$UNAME_RELEASE" | sed -e 's/-/_/'`
 	GUESS=sparc-sun-sunos$SUN_REL
 	;;
@@ -904,7 +908,7 @@ EOF
 	fi
 	;;
     *:FreeBSD:*:*)
-	UNAME_PROCESSOR=`/usr/bin/uname -p`
+	UNAME_PROCESSOR=`uname -p`
 	case $UNAME_PROCESSOR in
 	    amd64)
 		UNAME_PROCESSOR=x86_64 ;;
@@ -929,6 +933,9 @@ EOF
     i*:PW*:*)
 	GUESS=$UNAME_MACHINE-pc-pw32
 	;;
+    *:SerenityOS:*:*)
+        GUESS=$UNAME_MACHINE-pc-serenity
+        ;;
     *:Interix*:*)
 	case $UNAME_MACHINE in
 	    x86)
@@ -963,11 +970,37 @@ EOF
 	GNU_REL=`echo "$UNAME_RELEASE" | sed -e 's/[-(].*//'`
 	GUESS=$UNAME_MACHINE-unknown-$GNU_SYS$GNU_REL-$LIBC
 	;;
+    x86_64:[Mm]anagarm:*:*|i?86:[Mm]anagarm:*:*)
+	GUESS="$UNAME_MACHINE-pc-managarm-mlibc"
+	;;
+    *:[Mm]anagarm:*:*)
+	GUESS="$UNAME_MACHINE-unknown-managarm-mlibc"
+	;;
     *:Minix:*:*)
 	GUESS=$UNAME_MACHINE-unknown-minix
 	;;
     aarch64:Linux:*:*)
-	GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
+	set_cc_for_build
+	CPU=$UNAME_MACHINE
+	LIBCABI=$LIBC
+	if test "$CC_FOR_BUILD" != no_compiler_found; then
+	    ABI=64
+	    sed 's/^	    //' << EOF > "$dummy.c"
+	    #ifdef __ARM_EABI__
+	    #ifdef __ARM_PCS_VFP
+	    ABI=eabihf
+	    #else
+	    ABI=eabi
+	    #endif
+	    #endif
+EOF
+	    cc_set_abi=`$CC_FOR_BUILD -E "$dummy.c" 2>/dev/null | grep '^ABI' | sed 's, ,,g'`
+	    eval "$cc_set_abi"
+	    case $ABI in
+		eabi | eabihf) CPU=armv8l; LIBCABI=$LIBC$ABI ;;
+	    esac
+	fi
+	GUESS=$CPU-unknown-linux-$LIBCABI
 	;;
     aarch64_be:Linux:*:*)
 	UNAME_MACHINE=aarch64_be
@@ -1033,7 +1066,16 @@ EOF
     k1om:Linux:*:*)
 	GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
 	;;
-    loongarch32:Linux:*:* | loongarch64:Linux:*:* | loongarchx32:Linux:*:*)
+    kvx:Linux:*:*)
+	GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
+	;;
+    kvx:cos:*:*)
+	GUESS=$UNAME_MACHINE-unknown-cos
+	;;
+    kvx:mbr:*:*)
+	GUESS=$UNAME_MACHINE-unknown-mbr
+	;;
+    loongarch32:Linux:*:* | loongarch64:Linux:*:*)
 	GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
 	;;
     m32r*:Linux:*:*)
@@ -1148,16 +1190,27 @@ EOF
 	;;
     x86_64:Linux:*:*)
 	set_cc_for_build
+	CPU=$UNAME_MACHINE
 	LIBCABI=$LIBC
 	if test "$CC_FOR_BUILD" != no_compiler_found; then
-	    if (echo '#ifdef __ILP32__'; echo IS_X32; echo '#endif') | \
-		(CCOPTS="" $CC_FOR_BUILD -E - 2>/dev/null) | \
-		grep IS_X32 >/dev/null
-	    then
-		LIBCABI=${LIBC}x32
-	    fi
+	    ABI=64
+	    sed 's/^	    //' << EOF > "$dummy.c"
+	    #ifdef __i386__
+	    ABI=x86
+	    #else
+	    #ifdef __ILP32__
+	    ABI=x32
+	    #endif
+	    #endif
+EOF
+	    cc_set_abi=`$CC_FOR_BUILD -E "$dummy.c" 2>/dev/null | grep '^ABI' | sed 's, ,,g'`
+	    eval "$cc_set_abi"
+	    case $ABI in
+		x86) CPU=i686 ;;
+		x32) LIBCABI=${LIBC}x32 ;;
+	    esac
 	fi
-	GUESS=$UNAME_MACHINE-pc-linux-$LIBCABI
+	GUESS=$CPU-pc-linux-$LIBCABI
 	;;
     xtensa*:Linux:*:*)
 	GUESS=$UNAME_MACHINE-unknown-linux-$LIBC
@@ -1177,7 +1230,7 @@ EOF
 	GUESS=$UNAME_MACHINE-pc-sysv4.2uw$UNAME_VERSION
 	;;
     i*86:OS/2:*:*)
-	# If we were able to find `uname', then EMX Unix compatibility
+	# If we were able to find 'uname', then EMX Unix compatibility
 	# is probably installed.
 	GUESS=$UNAME_MACHINE-pc-os2-emx
 	;;
@@ -1318,7 +1371,7 @@ EOF
 		GUESS=ns32k-sni-sysv
 	fi
 	;;
-    PENTIUM:*:4.0*:*)	# Unisys `ClearPath HMP IX 4000' SVR4/MP effort
+    PENTIUM:*:4.0*:*)	# Unisys 'ClearPath HMP IX 4000' SVR4/MP effort
 			# says <Richard.M.Bartel@ccMail.Census.GOV>
 	GUESS=i586-unisys-sysv4
 	;;
@@ -1364,8 +1417,11 @@ EOF
     BePC:Haiku:*:*)	# Haiku running on Intel PC compatible.
 	GUESS=i586-pc-haiku
 	;;
-    x86_64:Haiku:*:*)
-	GUESS=x86_64-unknown-haiku
+    ppc:Haiku:*:*)	# Haiku running on Apple PowerPC
+	GUESS=powerpc-apple-haiku
+	;;
+    *:Haiku:*:*)	# Haiku modern gcc (not bound by BeOS compat)
+	GUESS=$UNAME_MACHINE-unknown-haiku
 	;;
     SX-4:SUPER-UX:*:*)
 	GUESS=sx4-nec-superux$UNAME_RELEASE
@@ -1522,6 +1578,9 @@ EOF
     i*86:rdos:*:*)
 	GUESS=$UNAME_MACHINE-pc-rdos
 	;;
+    i*86:Fiwix:*:*)
+	GUESS=$UNAME_MACHINE-pc-fiwix
+	;;
     *:AROS:*:*)
 	GUESS=$UNAME_MACHINE-unknown-aros
 	;;

config.h.in

@@ -3,19 +3,19 @@
 /* Define to 1 if you have the <dlfcn.h> header file. */
 #undef HAVE_DLFCN_H
 
-/* Define to 1 if you have the `feenableexcept' function. */
+/* Define to 1 if you have the 'feenableexcept' function. */
 #undef HAVE_FEENABLEEXCEPT
 
 /* Define to 1 if you have the <inttypes.h> header file. */
 #undef HAVE_INTTYPES_H
 
-/* Define to 1 if you have the `m' library (-lm). */
+/* Define to 1 if you have the 'm' library (-lm). */
 #undef HAVE_LIBM
 
-/* Define to 1 if you have the `z' library (-lz). */
+/* Define to 1 if you have the 'z' library (-lz). */
 #undef HAVE_LIBZ
 
-/* Define to 1 if you have the `pow' function. */
+/* Define to 1 if you have the 'pow' function. */
 #undef HAVE_POW
 
 /* Define to 1 if you have the <stdint.h> header file. */
@@ -108,12 +108,12 @@
 /* Enable POWERPC VSX optimizations */
 #undef PNG_POWERPC_VSX_OPT
 
-/* Define to 1 if all of the C90 standard headers exist (not just the ones
+/* Define to 1 if all of the C89 standard headers exist (not just the ones
    required in a freestanding environment). This macro is provided for
    backward compatibility; new code need not use it. */
 #undef STDC_HEADERS
 
-/* Define to 1 if your <sys/time.h> declares `struct tm'. */
+/* Define to 1 if your <sys/time.h> declares 'struct tm'. */
 #undef TM_IN_SYS_TIME
 
 /* Version number of package */