add empty line for style.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38591 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

thread.c

@@ -1701,6 +1701,7 @@ rb_thread_s_handle_interrupt(VALUE self, VALUE mask_arg)
 
     return r;
 }
+
 /*
  * call-seq:
  *   target_thread.pending_interrupt?(err = nil) -> true/false