Add native Windows binary for bison.

bison/src/bison/2.4.1/bison-2.4.1-src/m4/warnings.m4

Index: bison/src/bison/2.4.1/bison-2.4.1-src/m4/warnings.m4
===================================================================
--- bison/src/bison/2.4.1/bison-2.4.1-src/m4/warnings.m4	(revision 0)
+++ bison/src/bison/2.4.1/bison-2.4.1-src/m4/warnings.m4	(revision 0)
@@ -0,0 +1,44 @@
+# warnings.m4 serial 2
+dnl Copyright (C) 2008 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 From Simon Josefsson
+
+# gl_AS_VAR_IF(VAR, VALUE, [IF-MATCH], [IF-NOT-MATCH])
+# ----------------------------------------------------
+# Provide the functionality of AS_VAR_IF if Autoconf does not have it.
+m4_ifdef([AS_VAR_IF],
+[m4_copy([AS_VAR_IF], [gl_AS_VAR_IF])],
+[m4_define([gl_AS_VAR_IF],
+[AS_IF([test x"AS_VAR_GET([$1])" = x""$2], [$3], [$4])])])
+
+# gl_AS_VAR_APPEND(VAR, VALUE)
+# ----------------------------
+# Provide the functionality of AS_VAR_APPEND if Autoconf does not have it.
+m4_ifdef([AS_VAR_APPEND],
+[m4_copy([AS_VAR_APPEND], [gl_AS_VAR_APPEND])],
+[m4_define([gl_AS_VAR_APPEND],
+[AS_VAR_SET([$1], [AS_VAR_GET([$1])$2])])])
+
+# gl_WARN_ADD(PARAMETER, [VARIABLE = WARN_CFLAGS])
+# ------------------------------------------------
+# Adds parameter to WARN_CFLAGS if the compiler supports it.  For example,
+# gl_WARN_ADD([-Wparentheses]).
+AC_DEFUN([gl_WARN_ADD],
+[AS_VAR_PUSHDEF([gl_Warn], [gl_cv_warn_$1])dnl
+AC_CACHE_CHECK([whether compiler handles $1], [gl_Warn], [
+  save_CPPFLAGS="$CPPFLAGS"
+  CPPFLAGS="${CPPFLAGS} $1"
+  AC_PREPROC_IFELSE([AC_LANG_PROGRAM([])],
+                    [AS_VAR_SET([gl_Warn], [yes])],
+		    [AS_VAR_SET([gl_Warn], [no])])
+  CPPFLAGS="$save_CPPFLAGS"
+])
+AS_VAR_PUSHDEF([gl_Flags], m4_if([$2], [], [[WARN_CFLAGS]], [[$2]]))dnl
+gl_AS_VAR_IF([gl_Warn], [yes], [gl_AS_VAR_APPEND([gl_Flags], [" $1"])])
+AS_VAR_POPDEF([gl_Flags])dnl
+AS_VAR_POPDEF([gl_Warn])dnl
+m4_ifval([$2], [AS_LITERAL_IF([$2], [AC_SUBST([$2])], [])])dnl
+])