BUG: parser_source as a filename with multibyte characters in Windows(non utf-8 filesystem)

fopen() in Windows doesn't accept utf-8 encoded filename with multibyte characters, so need to convert it to filesystem encoding.
Set 'utf-8' as default in case sys.getfilesystemencoding() return None.
sys.getfilesystemencoding() will return 'mbcs' in Windows, and will 'utf-8' or user setting in other systems.