gdb, gdbserver, gdbsupport: use AC_CANONICAL_{BUILD,HOST,TARGET} instead of AC_CANONICAL_SYSTEM

`autoreconf -Wall` notes that AC_CANONICAL_SYSTEM is obsolete:

    configure.ac:36: warning: The macro `AC_CANONICAL_SYSTEM' is obsolete.

Replace it by AC_CANONICAL_BUILD, AC_CANONICAL_HOST and
AC_CANONICAL_TARGET in configure.ac files in gdb, gdbserver and
gdbsupport.  All three macros may not be needed everywhere, but it is
hard to completely audit the configure files to see which are required,
so I think it's better (and that there's no downside) to just call all
three.

gdb/ChangeLog:

	* configure.ac: Use AC_CANONICAL_{BUILD,HOST,TARGET} instead of
	AC_CANONICAL_SYSTEM.
	* configure: Re-generate.

gdbserver/ChangeLog:

	* configure.ac: Use AC_CANONICAL_{BUILD,HOST,TARGET} instead of
	AC_CANONICAL_SYSTEM.
	* configure: Re-generate.

gdbsupport/ChangeLog:

	* configure.ac: Use AC_CANONICAL_{BUILD,HOST,TARGET} instead of
	AC_CANONICAL_SYSTEM.
	* configure: Re-generate.

Change-Id: Ifd0e21f1e478634e768b5de1b8ee06a7f690d863

gdb/configure

@@ -5249,6 +5249,15 @@ ac_configure="$SHELL $ac_aux_dir/configure"  # Please don't use this var.
 
 
 
+# Set build, build_cpu, build_vendor and build_os.
+
+
+# Set host, host_cpu, host_vendor, and host_os.
+
+
+# Set target, target_cpu, target_vendor, and target_os.
+
+
 test "$program_prefix" != NONE &&
   program_transform_name="s&^&$program_prefix&;$program_transform_name"
 # Use a double $ so make ignores it.

gdb/configure.ac

@@ -33,7 +33,16 @@ AM_PROG_CC_STDC
 AM_PROG_INSTALL_STRIP
 
 AC_CONFIG_AUX_DIR(..)
-AC_CANONICAL_SYSTEM
+
+# Set build, build_cpu, build_vendor and build_os.
+AC_CANONICAL_BUILD
+
+# Set host, host_cpu, host_vendor, and host_os.
+AC_CANONICAL_HOST
+
+# Set target, target_cpu, target_vendor, and target_os.
+AC_CANONICAL_TARGET
+
 AC_ARG_PROGRAM
 
 # We require a C++11 compiler.  Check if one is available, and if

gdbserver/configure

@@ -4588,6 +4588,7 @@ fi
 INSTALL_STRIP_PROGRAM="\$(install_sh) -c -s"
 
 
+# Set build, build_cpu, build_vendor and build_os.
 # Make sure we can run config.sub.
 $SHELL "$ac_aux_dir/config.sub" sun4 >/dev/null 2>&1 ||
   as_fn_error $? "cannot run $SHELL $ac_aux_dir/config.sub" "$LINENO" 5
@@ -4626,6 +4627,8 @@ IFS=$ac_save_IFS
 case $build_os in *\ *) build_os=`echo "$build_os" | sed 's/ /-/g'`;; esac
 
 
+
+# Set host, host_cpu, host_vendor, and host_os.
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking host system type" >&5
 $as_echo_n "checking host system type... " >&6; }
 if ${ac_cv_host+:} false; then :
@@ -4659,6 +4662,8 @@ IFS=$ac_save_IFS
 case $host_os in *\ *) host_os=`echo "$host_os" | sed 's/ /-/g'`;; esac
 
 
+
+# Set target, target_cpu, target_vendor, and target_os.
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking target system type" >&5
 $as_echo_n "checking target system type... " >&6; }
 if ${ac_cv_target+:} false; then :
@@ -4699,7 +4704,6 @@ test -n "$target_alias" &&
     NONENONEs,x,x, &&
   program_prefix=${target_alias}-
 
-
 # Find a good install program.  We prefer a C program (faster),
 # so one script is as good as another.  But avoid the broken or
 # incompatible versions:

gdbserver/configure.ac

@@ -29,7 +29,14 @@ AC_GNU_SOURCE
 AC_SYS_LARGEFILE
 AM_PROG_INSTALL_STRIP
 
-AC_CANONICAL_SYSTEM
+# Set build, build_cpu, build_vendor and build_os.
+AC_CANONICAL_BUILD
+
+# Set host, host_cpu, host_vendor, and host_os.
+AC_CANONICAL_HOST
+
+# Set target, target_cpu, target_vendor, and target_os.
+AC_CANONICAL_TARGET
 
 AC_PROG_INSTALL
 AC_CHECK_TOOL(AR, ar)

gdbsupport/configure

@@ -2728,6 +2728,8 @@ ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
 ac_config_headers="$ac_config_headers config.h:config.in"
 
+
+# Set build, build_cpu, build_vendor and build_os.
 ac_aux_dir=
 for ac_dir in "$srcdir" "$srcdir/.." "$srcdir/../.."; do
   if test -f "$ac_dir/install-sh"; then
@@ -2795,6 +2797,8 @@ IFS=$ac_save_IFS
 case $build_os in *\ *) build_os=`echo "$build_os" | sed 's/ /-/g'`;; esac
 
 
+
+# Set host, host_cpu, host_vendor, and host_os.
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking host system type" >&5
 $as_echo_n "checking host system type... " >&6; }
 if ${ac_cv_host+:} false; then :
@@ -2828,6 +2832,8 @@ IFS=$ac_save_IFS
 case $host_os in *\ *) host_os=`echo "$host_os" | sed 's/ /-/g'`;; esac
 
 
+
+# Set target, target_cpu, target_vendor, and target_os.
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking target system type" >&5
 $as_echo_n "checking target system type... " >&6; }
 if ${ac_cv_target+:} false; then :

gdbsupport/configure.ac

@@ -19,7 +19,16 @@ dnl Process this file with autoconf to produce a configure script.
 AC_INIT([gdbsupport], 1.0)
 AC_CONFIG_SRCDIR(common-defs.h)
 AC_CONFIG_HEADER(config.h:config.in)
-AC_CANONICAL_SYSTEM
+
+# Set build, build_cpu, build_vendor and build_os.
+AC_CANONICAL_BUILD
+
+# Set host, host_cpu, host_vendor, and host_os.
+AC_CANONICAL_HOST
+
+# Set target, target_cpu, target_vendor, and target_os.
+AC_CANONICAL_TARGET
+
 AM_MAINTAINER_MODE
 AC_CONFIG_AUX_DIR(..)
 AM_INIT_AUTOMAKE