Remove obsolete macros from several modules. * m4/c-stack.m4 (AC_SYS_XSI_STACK_OVERFLOW_HEURISTIC): Replace obsolete Autoconf macros with their modern counterparts. * m4/check-math-lib.m4 (gl_CHECK_MATH_LIB): Likewise. * m4/gc-camellia.m4 (gl_GC_CAMELLIA): Likewise. * m4/getaddrinfo.m4 (gl_GETADDRINFO): Likewise. * m4/getdate.m4 (gl_C_COMPOUND_LITERALS): Likewise. * m4/gethostname.m4 (gl_FUNC_GETHOSTNAME): Likewise. * m4/getline.m4 (gl_FUNC_GETLINE): Likewise. * m4/getopt.m4 (gl_GETOPT_CHECK_HEADERS): Likewise. * m4/isfinite.m4 (gl_ISFINITEL_WORKS): Likewise. * m4/poll.m4 (gl_FUNC_POLL): Likewise. * m4/readline.m4 (gl_FUNC_READLINE): Likewise. * m4/round.m4 (gl_FUNC_ROUND): Likewise. * m4/roundf.m4 (gl_FUNC_ROUNDF): Likewise. * m4/select.m4 (gl_FUNC_SELECT): Likewise. * m4/sockets.m4 (gl_SOCKETS): Likewise. * m4/socklen.m4 (gl_TYPE_SOCKLEN_T): Likewise. * m4/sockpfaf.m4 (gl_SOCKET_FAMILIES): Likewise. * m4/sysexits.m4 (gl_SYSEXITS): Likewise. * m4/time_r.m4 (gl_TIME_R): Likewise. * m4/tsearch.m4 (gl_FUNC_TSEARCH): Likewise. * m4/vararrays.m4 (AC_C_VARARRAYS): Likewise. * m4/wctype.m4 (gl_WCTYPE_H): Likewise. Signed-off-by: Ralf Wildenhues <Ralf.Wildenhues@gmx.de>

# check-math-lib.m4 serial 3
dnl Copyright (C) 2007 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.
dnl
dnl gl_CHECK_MATH_LIB (VARIABLE, EXPRESSION)
dnl
dnl Sets the shell VARIABLE according to the libraries needed by EXPRESSION
dnl to compile and link: to the empty string if no extra libraries are needed,
dnl to "-lm" if -lm is needed, or to "missing" if it does not compile and
dnl link either way.
dnl
dnl Example: gl_CHECK_MATH_LIB([ROUNDF_LIBM], [x = roundf (x);])
AC_DEFUN([gl_CHECK_MATH_LIB], [
  save_LIBS=$LIBS
  $1=missing
  for libm in "" "-lm"; do
    LIBS="$save_LIBS $libm"
    AC_LINK_IFELSE([AC_LANG_PROGRAM([[
         #ifndef __NO_MATH_INLINES
         # define __NO_MATH_INLINES 1 /* for glibc */
         #endif
         #include <math.h>
         double x;]],
      [$2])],
      [$1=$libm
break])
  done
  LIBS=$save_LIBS
])