fix(ext/web): ReadableStream.from() async from iterator

`createAsyncFromSyncIterator(x)` expects `x` as `Iterable` but, previous
implements specify `Iterator` or `IterableIterator`. If it was
`IterableIterator`, it would work, but if it was `Iterator`, an
exception will occur.

Tests have been merged into WPT.
web-platform-tests/wpt#46365

ext/web/06_streams.js

@@ -5100,7 +5100,7 @@ function getIterator(obj, async = false) {
  if (obj[SymbolIterator] === undefined) {
  throw new TypeError("No iterator found");
  }
- return createAsyncFromSyncIterator(obj[SymbolIterator]());
+ return createAsyncFromSyncIterator(obj);
  } else {
  return obj[SymbolAsyncIterator]();
  }