Made MAX_UNTIL/MIN_UNTIL code more coherent about mark protection, accordingly to further discussions with Greg Chapman in patch #712900.
Made MAX_UNTIL/MIN_UNTIL code more coherent about mark protection,
accordingly to further discussions with Greg Chapman in patch #712900.

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator