Describe the new feature or change to an existing feature you'd like to see

I'm currently implementing an amp-nested-menu into a sidebar where I'm receiving amp validation errors for using SVG's with the <use> tag as well as similar errors using a <select> tag.

Describe alternatives you've considered

We could use an <amp-img> referencing the svg as a src rather than use inline svg tags. However, this would require some significant refactoring of our current AMP platform to serve these svg's.

Alternatives for <select>. While we could implement this as a standard html list we have deliberately used a <select> tag so our users can use their devices with native select UI instead of a custom html selector.

Additional context

Displaying a right angle arrow alongside some navigation text shown in the screenshot below:

The paired back mark-up looks like this:

<h4 amp-nested-submenu-open="">
  Accessories 
  <svg width="15" height="15" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 32 32">
    <use height="15" width="15" href="#svg_angle-right" xlink:href="#svg_angle-right"></use>
  </svg>
</h4>

As you can see, rather than rendering the svg content directly we re-use the same svg multiple times using the tag.

These tags seem to be missing from validator-amp-nested-menu.protoascii, presumably they just need to be added to the list?