See the original report in https://github.com/facebook/react/issues/10772#issuecomment-333242375.

The problem is that SVG is case sensitive, and so naïvely setting `tabIndex` and relying on insensitivity won't work with it.

The good news is it seems like `tabindex` is the only valid [SVG attribute](https://developer.mozilla.org/en-US/docs/Web/SVG/Attribute) with this problem. We just missed it because it applies both to HTML and SVG.

I think the fix is to add it back to the whitelist. 
const domElement = await serverRender(serverElement);
  resetModules();
  return renderIntoDom(
    clientElement,
    domElement.parentNode,
    true,
    shouldMatch ? 0 : 1,
  );
}
function expectMarkupMatch(serverElement, clientElement) {
  return testMarkupMatch(serverElement, clientElement, true);
}
function expectMarkupMismatch(serverElement, clientElement) {
  return testMarkupMatch(serverElement, clientElement, false);
}
function resetModules() {