Fix build when BATCH and WITH_ONIGURUMA is set.

PR:		ports/87704
Submitted by:	IWATSUKI Hiroyuki <don@na.rim.or.jp>
Reviewed by:	Parv <parv@pair.com>

lang/ruby18/files/patch-ext_extmk.rb

@@ -0,0 +1,25 @@
+--- ext/extmk.rb	6 Feb 2005 15:13:50 -0000	1.44.2.8
++++ ext/extmk.rb	2 Mar 2005 10:53:20 -0000	1.44.2.9
+@@ -157,6 +157,10 @@ def parse_args()
+     grep(/\A-(?!-).*#{'%c' % flag}/i) { return true }
+     false
+   end
++  def $mflags.defined?(var)
++    grep(/\A#{var}=(.*)/) {return $1}
++    false
++  end
+ 
+   if $mflags.set?(?n)
+     $dryrun = true
+@@ -165,7 +169,10 @@ def parse_args()
+   end
+ 
+   $continue = $mflags.set?(?k)
+-  $mflags |= ["DESTDIR=#{$destdir}"]
++  if !$destdir.to_s.empty?
++    $destdir = File.expand_path($destdir)
++    $mflags.defined?("DESTDIR") or $mflags << "DESTDIR=#{$destdir}"
++  end
+ end
+ 
+ parse_args()