@foolip @Elchi3 can you explain this in a little more detail? Was this never actually supported or was it dropped and now being removed as irrelevant? Something else?

I ask because I don't know what to write in the release notes for this one.

My understanding of this PR is that these were renamed to
https://developer.mozilla.org/en-US/docs/Web/API/ConstrainULong
https://developer.mozilla.org/en-US/docs/Web/API/ULongRange

and the old names were dropped and now are now being removed as irrelevant here.

Very helpful, thank you!

It actually doesn't matter whether these types were ever used in implementations or not, because it amounts to changing a signed integer to an unsigned one. This has happened a lot (I've done a lot of such spec matching) but it's almost always the case that the values that are actually returned are unchanged. In JS there are only numbers, so a change like this is usually impossible to observe, unless some place that could return a negative number is also updated at the same time.