enable hl unit tests (close #6311)

tests/unit/compile.hxml

@@ -16,6 +16,7 @@ compile-java-runner.hxml
 
 --next compile-flash9.hxml
 --next compile-js.hxml
+--next compile-hl.hxml
 --next compile-lua.hxml
 --next compile-neko.hxml
 --next compile-php.hxml