bindings: Support Web IDL async iterable (5 of 5)

Supports extended attributes applied to async iterable declaration.
For example,
```
[Exposed=Window] async iterable<DOMString, long>;
```

The effect of the extended attributes is to control the exposure of
async iterable operations such as "keys", "values", "entries", and
@@asyncIterator.

An usage is demonstrated at https://crrev.com/c/4759045 .

Bug: 1087157
Change-Id: Ibc3725f0c27fb9a99e14223b1bf5793d70f9ebd9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4931169
Reviewed-by: Raphael Kubo Da Costa <raphael.kubo.da.costa@intel.com>
Commit-Queue: Yuki Shiino <yukishiino@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1209344}
NOKEYCHECK=True
GitOrigin-RevId: 3c7d2f8efa5ef2471ff790236c1a17281c4cd5b4
1 file changed