* include/ruby/missing.h (isnan): fix compilation error on OpenBSD.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@28280 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,7 @@
+Fri Jun 11 22:59:31 2010  Tanaka Akira  <akr@fsij.org>
+
+	* include/ruby/missing.h (isnan): fix compilation error on OpenBSD.
+
 Fri Jun 11 22:39:50 2010  Yusuke Endoh  <mame@tsg.ne.jp>
 
 	* lib/rubygems/install_update_options.rb

include/ruby/missing.h

@@ -112,8 +112,10 @@ RUBY_EXTERN int isinf(double);
 # endif
 #endif
 
-#ifndef HAVE_ISNAN
+#ifndef isnan
+# ifndef HAVE_ISNAN
 RUBY_EXTERN int isnan(double);
+# endif
 #endif
 
 /*