Follow up from May 2025 iterator sequencing update

[ptomato]

Per @iamstolis in #4523 (comment)

Shouldn't built-ins/Iterator/concat/next-method-returns-throwing-value.js be updated as well? iterator.next() did not throw before because iteratorResult was reused (i.e. its value was not read). Now, IteratorStepValue() always reads the value of the inner iterator (which throws in this case). So, iterator.next() should throw now, right?

In other words, I think that 71794b1 should be reverted now.

[ptomato]

cc @michaelficarra - can you please check if this matches your understanding?

[michaelficarra]

Yes, this sounds correct. It looks like I missed reverting that commit.