Upgrade to Autoconf 2.61:

- Change configure.in to use Autoconf 2.61 and update generated files.
- Update build system and documentation to support now directory variables
  offered by Autoconf 2.61.
- Replace usages of PGAC_CHECK_ALIGNOF by AC_CHECK_ALIGNOF, now available
  in Autoconf 2.61.
- Drop our patched version of AC_C_INLINE, as Autoconf now has the change.

config/c-compiler.m4

@@ -1,5 +1,5 @@
 # Macros to detect C compiler features
-# $PostgreSQL: pgsql/config/c-compiler.m4,v 1.14 2004/12/16 17:48:25 momjian Exp $
+# $PostgreSQL: pgsql/config/c-compiler.m4,v 1.15 2008/02/17 16:36:42 petere Exp $
 
 
 # PGAC_C_SIGNED
@@ -70,32 +70,6 @@ undefine([Ac_cachevar])dnl
 
 
 
-# PGAC_CHECK_ALIGNOF(TYPE, [INCLUDES = DEFAULT-INCLUDES])
-# -----------------------------------------------------
-# Find the alignment requirement of the given type. Define the result
-# as ALIGNOF_TYPE.  This macro works even when cross compiling.
-# (Modelled after AC_CHECK_SIZEOF.)
-
-AC_DEFUN([PGAC_CHECK_ALIGNOF],
-[AS_LITERAL_IF([$1], [],
-               [AC_FATAL([$0: requires literal arguments])])dnl
-AC_CHECK_TYPE([$1], [], [], [$2])
-AC_CACHE_CHECK([alignment of $1], [AS_TR_SH([pgac_cv_alignof_$1])],
-[if test "$AS_TR_SH([ac_cv_type_$1])" = yes; then
-  _AC_COMPUTE_INT([((char*) & pgac_struct.field) - ((char*) & pgac_struct)],
-                  [AS_TR_SH([pgac_cv_alignof_$1])],
-                  [AC_INCLUDES_DEFAULT([$2])
-struct { char filler; $1 field; } pgac_struct;],
-                  [AC_MSG_ERROR([cannot compute alignment of $1, 77])])
-else
-  AS_TR_SH([pgac_cv_alignof_$1])=0
-fi])dnl
-AC_DEFINE_UNQUOTED(AS_TR_CPP(alignof_$1),
-                   [$AS_TR_SH([pgac_cv_alignof_$1])],
-                   [The alignment requirement of a `$1'.])
-])# PGAC_CHECK_ALIGNOF
-
-
 # PGAC_C_FUNCNAME_SUPPORT
 # -----------------------
 # Check if the C compiler understands __func__ (C99) or __FUNCTION__ (gcc).
@@ -121,6 +95,8 @@ AC_DEFINE(HAVE_FUNCNAME__FUNCTION, 1,
 fi
 fi])# PGAC_C_FUNCNAME_SUPPORT
 
+
+
 # PGAC_PROG_CC_CFLAGS_OPT
 # -----------------------
 # Given a string, check if the compiler supports the string as a
@@ -134,42 +110,3 @@ _AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],
                    [CFLAGS="$pgac_save_CFLAGS"
                     AC_MSG_RESULT(no)])
 ])# PGAC_PROG_CC_CFLAGS_OPT
-
-# The below backpatches the following Autoconf change:
-#
-# 2002-03-28  Kevin Ryde  <user42@zip.com.au>
-#
-#         * lib/autoconf/c.m4 (AC_C_INLINE): Test with a typedef return value,
-#         to avoid versions of HP C which don't allow that.
-#
-# When we upgrade to Autoconf >= 2.53a then we can drop this and rely
-# on the standard macro.
-
-# AC_C_INLINE
-# -----------
-# Do nothing if the compiler accepts the inline keyword.
-# Otherwise define inline to __inline__ or __inline if one of those work,
-# otherwise define inline to be empty.
-AC_DEFUN([AC_C_INLINE],
-[AC_REQUIRE([AC_PROG_CC_STDC])dnl
-AC_CACHE_CHECK([for inline], ac_cv_c_inline,
-[ac_cv_c_inline=no
-for ac_kw in inline __inline__ __inline; do
-  AC_COMPILE_IFELSE([AC_LANG_SOURCE(
-[#ifndef __cplusplus
-typedef int foo_t;
-static $ac_kw foo_t static_foo () {return 0; }
-$ac_kw int foo () {return 0; }
-#endif
-])],
-                    [ac_cv_c_inline=$ac_kw; break])
-done
-])
-case $ac_cv_c_inline in
-  inline | yes) ;;
-  no) AC_DEFINE(inline,,
-                [Define as `__inline' if that's what the C compiler calls it,
-                 or to nothing if it is not supported.]) ;;
-  *)  AC_DEFINE_UNQUOTED(inline, $ac_cv_c_inline) ;;
-esac
-])# AC_C_INLINE