configure.in: escape

* configure.in (configure_args): escape $ for Makefile.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39176 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

configure.in

@@ -3332,8 +3332,7 @@ AC_SUBST(vendordir)dnl
 AC_SUBST(vendorlibdir)dnl
 AC_SUBST(vendorarchdir)dnl
 
-configure_args=$ac_configure_args
-AC_SUBST(configure_args)dnl
+AC_SUBST(configure_args, "`echo "${ac_configure_args}" | sed 's/\\$/$$/g'`")dnl
 
 if test "${universal_binary-no}" = yes ; then
     arch="universal-${target_os}"