Fix some porting glitches found by Nelson H. F. Beebe.

* lib/abitset.c (abitset_resize): Rewrite to avoid warnings from
compilers that don't understand that abort () does not return.
* src/state.c (transitions_to): Likewise.
* m4/cxx.m4 (BISON_TEST_FOR_WORKING_CXX_COMPILER): Check
that '#include <cstdlib>' works.
* src/system.h (INT8_MIN, INT16_MIN, INT32_MIN, INT8_MAX):
(INT16_MAX, UINT8_MAX, INT32_MAX, UINT16_MAX, UINT32_MAX):
#undef if ! defined __STDC_VERSION__ || __STDC_VERSION__ < 199901,
for the benefit of some pre-C99 compilers.

m4/cxx.m4

@@ -1,7 +1,7 @@
 # -*- Autoconf -*-
 # Sanity-test a C++ compiler.
 #
-# Copyright (C) 2004 Free Software Foundation, Inc.
+# Copyright (C) 2004, 2006 Free Software Foundation, Inc.
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -18,7 +18,7 @@
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 # 02110-1301  USA
 
-# Written by Paul Eggert <eggert@cs.ucla.edu>.
+# Written by Paul Eggert.
 
 AC_DEFUN([BISON_TEST_FOR_WORKING_CXX_COMPILER],
 [
@@ -27,7 +27,8 @@ AC_DEFUN([BISON_TEST_FOR_WORKING_CXX_COMPILER],
    [AC_LANG_PUSH([C++])
     AC_RUN_IFELSE(
       [AC_LANG_PROGRAM(
-	 [#include <iostream>
+	 [#include <cstdlib>
+	  #include <iostream>
 	  using namespace std;],
          [std::cerr << "";
           cout << "";])],