_isdst crashes with big dates on x86

[Dzmitry Dzemidzenka]

timestamp = ((dt.toordinal() - EPOCHORDINAL) * 86400
                     + dt.hour * 3600
                     + dt.minute * 60
                     + dt.second)
        return time.localtime(timestamp+time.timezone).tm_isdst

The code above is failing because of the overflow on 32bit systems for dates like '2049-06-20T12:34:40+03:00'

ValueError('timestamp out of range for platform time_t',)