Changes due to stage 3 reviews to present in July 2023

[nicolo-ribaudo]

The bar for changes to the proposal is now high, but there are some changes that are either already part of the proposal spec or are planned. I will bring these up for consensus at the July TC39 meeting.

• [ ] Collect all the attributes in dynamic import before validating them (https://github.com/tc39/proposal-import-attributes/issues/137#issuecomment-1518313840). The difference between the old and the new behavior is currently not tested neither by test262 not by V8's tests, so regardless of what we decide we should add a test for this.
• [ ] Remove the [no LineTerminator here] restriction before with. This was necessary with assert to avoid ASI ambiguities, but given that with is a reserved word we don't have this problem anymore. I noticed this wile implementing the proposal in Babel, and it has also been reported at https://github.com/tc39/proposal-import-attributes/issues/136.
• [ ] Allow any LiteralPropertyName in import attributes keys, making with { 0: "a", 1n: "b" } syntactically valid. This is for consistency with objects, and thus with the dynamic import form. (https://github.com/tc39/ecma262/pull/3057#pullrequestreview-1478139922)

[nicolo-ribaudo]

Slides: https://docs.google.com/presentation/d/1XKSeyxhCiSrzqJRqZ6ioYeqHh72oBHkd9izufPiRktY

[nicolo-ribaudo]

Consensus on all these changes. However, after plenary I received this feedback from SpiderMonkey: https://github.com/tc39/proposal-import-attributes/issues/145