Pass .java files through compiler untouched

This way they'll get included in the javac command line wth the
--javac option:

jrubyc --javac ruby_file.rb SomeOtherClass.java

lib/ruby/site_ruby/shared/jruby/compiler.rb

@@ -192,7 +192,11 @@ def compile_files_with_options(filenames, options = default_options)
           errors += compile_proc[filename]
 	}
       else
-        errors += compile_proc[filename]
+        if filename =~ /\.java$/
+          files << filename
+        else
+          errors += compile_proc[filename]
+        end
       end
     end