dillon1000/react

Continue over ID-less children in ReactMount.findComponentRoot.

This fixes our perf test by coping with edge cases like the
injection of `<tbody>` between `<table>` and `<tr>` nodes, which occurs
automatically in some browsers when we set `.innerHTML`.

Introducing more search branches would be risky if not for my previous
commit that made `findComponentRoot` breadth-first instead of depth-first.