Editorial: Remove unnecessary specification of supportedLocalesOf length properties

[gibson042]

Some but not all supportedLocalesOf definitions explicitly specify length, but none of them should need to. However, we might consider updating https://tc39.es/ecma402/#conventions to explicitly adopt https://tc39.es/ecma262/#sec-ecmascript-standard-built-in-objects

Every built-in function object, including constructors, has a "length" property whose value is a non-negative integral Number. Unless otherwise specified, this value is equal to the number of required parameters shown in the subclause heading for the function description. Optional parameters and rest parameters are not included in the parameter count.

[ryzokuken]

Thanks, LGTM. What about the addition to conventions that you mention? Will you add another commit or should we go for a second PR?

[anba]

However, we might consider updating https://tc39.es/ecma402/#conventions to explicitly adopt https://tc39.es/ecma262/#sec-ecmascript-standard-built-in-objects

That's already part of https://tc39.es/ecma402/#requirements.

[gibson042]

Great!

[ryzokuken]

Looks like everything is in order, merging!

Thanks @gibson042 @anba and @ljharb