statically catch duplicate attributes

[alokmenghrajani]

When I try to compile the following snippet, it compiles fine:

function start(_) {
  Resource.styled_page("", [],
    <>                                                                                                                                                               
      <div id="1" id="2">hi</div>                                                                                                                                    
    </>
  )
}

Server.start(
  Server.http,
  [{dispatch: start}]
)

However, Firefox will not render a page with invalid xml (duplicate id attribtues).