Numeric type of Intl.DateTimeFormat [[FractionalSecondDigits]]

[ptomato]

(Follow up from #715 (comment))

There is an inconsistency about whether [[FractionalSecondDigits]] contains a Number or mathematical value. Properties of Intl.DateTimeFormat instances says either undefined or a "positive non-zero integer Number value" but step 36.d of InitializeDateTimeFormat arguably stores a mathematical value (returned from GetNumberOption in step 36.b.i) in the slot. In FormatDateTimePattern the value is passed to CreateDataPropertyOrThrow in step 12.b which suggests a Number value, but in 15.c.ii it's used in a mixed mathematical/Number value calculation which is an editorial error.

(I say "arguably stores a mathematical value" because GetNumberOption/DefaultNumberOption return a Number value, but it is compared against mathematical values minimum and maximum, and the operation floor() is applied to it, all of which are only valid for mathematical values.)

[gibson042]

Reated: #648

[anba]

#822 should fix this issue.

[sffc]

#822 is merged so I assume this issue is fixed. If it is not fixed, please re-open.