NewAKString is effectively the default for any new IDL interface, so
let's mark this as the default behavior. It also makes it much easier to
figure out whatever interfaces are still left to port over to new AK
String.
Stop worrying about tiny OOMs. Work towards #20449.
While going through these, I also changed the function signature in many
places where returning ThrowCompletionOr<T> is no longer necessary.
Rather than splitting the Iterator type and its AOs into two files,
let's combine them into one file to match every other JS runtime object
that we have.
This is an editorial change in the ECMA-262 spec. See:
https://github.com/tc39/ecma262/commit/956e5af
This splits the GetIterator AO into two AOs, to remove some recursion
and to (soon) remove optional parameters.
