Support x32 ABI.

Fix autoconf test checking whether mp_limb_t needs to be long long,
which is needed on x32.

include/cln/object.h

@@ -22,10 +22,10 @@ namespace cln {
 #if defined(__m68k__)
   #define cl_word_alignment  2
 #endif
-#if defined(__i386__) || defined(__mips__) || defined(__mipsel__) || (defined(__sparc__) && !defined(__arch64__)) || defined(__hppa__) || defined(__arm__) || defined(__rs6000__) || defined(__m88k__) || defined(__convex__) || (defined(__s390__) && !defined(__s390x__)) || defined(__sh__)
+#if defined(__i386__) || defined(__mips__) || defined(__mipsel__) || (defined(__sparc__) && !defined(__arch64__)) || defined(__hppa__) || defined(__arm__) || defined(__rs6000__) || defined(__m88k__) || defined(__convex__) || (defined(__s390__) && !defined(__s390x__)) || defined(__sh__) || (defined(__x86_64__) && defined(__ILP32__))
   #define cl_word_alignment  4
 #endif
-#if defined(__alpha__) || defined(__ia64__) || defined(__mips64__) || defined(__powerpc64__) || (defined(__sparc__) && defined(__arch64__)) || defined(__x86_64__) || defined(__s390x__)
+#if defined(__alpha__) || defined(__ia64__) || defined(__mips64__) || defined(__powerpc64__) || (defined(__sparc__) && defined(__arch64__)) || (defined(__x86_64__) && !defined(__ILP32__)) || defined(__s390x__)
   #define cl_word_alignment  8
 #endif
 #if !defined(cl_word_alignment)

m4/gmp.m4

@@ -52,7 +52,7 @@ AC_DEFUN([CL_GMP_SET_UINTD],
     AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <gmp.h>
 	 template<bool COND> struct Static_Assert;
 	 template<> struct Static_Assert<true> { };
-	 Static_Assert<sizeof(mp_limb_t) > sizeof(long)> check;]], [[]])],
+	 Static_Assert<(sizeof(mp_limb_t) > sizeof(long))> check;]], [[]])],
 	 [cl_gmp_demands='GMP_DEMANDS_UINTD_LONG_LONG'], [])
     if test "x$cl_gmp_demands" = "xUNKNOWN"; then
 	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <gmp.h>