This web API is alternative API to `throw e`, which is why we can reuse
a lot of the existing machinery.
The one testcase that isn't passing yet is because it reports an empty
`TypeError`. The current logic in `ErrorInfo` only retrieves the message
data, but doesn't include the type of the exception. For that, we need
to use `(*report)._base.errorNumber` and map that back to the original
type codes. However, deferring that to a follow-up as that requires some
more work in mozjs.
Signed-off-by: Tim van der Lippe <tvanderlippe@gmail.com>