Investigate 353-day Islamic years

[sffc]

The calendarical calculations return 353-day Islamic years for years including the following:

(ObservationalIslamic) Found year -269 AH with length 353
(ObservationalIslamic) Found year -40 AH with length 353
(ObservationalIslamic) Found year 168 AH with length 353
(ObservationalIslamic) Found year 670 AH with length 353
(ObservationalIslamic) Found year 763 AH with length 353
(ObservationalIslamic) Found year 1107 AH with length 353
(SaudiIslamic) Found year 454 AH with length 353
(SaudiIslamic) Found year 669 AH with length 353
(SaudiIslamic) Found year 899 AH with length 353

Investigate and fix the math.

Previous discussion: #4904 (comment)

[roozbehp]

It looks like 353-day Hijri years may also happen in real life. We are gathering data for use of Hijri calendar in Iran, and the sources I've looked into by now seem to show that 1401 AH was 353 days in Iran. It started on 1980-11-10 and ended on 1981-10-28.