Cramped style not respected

Created by: NSoiffer

Issue Summary

I find this surprising enough to think that maybe I'm doing something wrong (and I didn't find an issue about this)...

TeX has a notion of "cramped" which causes superscripts to be lower in a number of cases such as in accents, overlines, fractions (denominators), and subscripts. Here's a latex rendering:

The position of the '2' in x^2 is lowered in first instance except for the fraction, where it is the second instance (the denominator).

However, MathJax doesn't reduce the superscript position. Here's a codepen that shows that. Here's a screen shot of that:

[To be honest, my sons happened to be looking at what I was doing and liked the MathJax rendering better...]

Steps to Reproduce:

This is the header

<script src="https://polyfill.io/v3/polyfill.min.js?features=es6"></script>
  <script type="text/javascript" id="MathJax-script" async
  src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-chtml.js">
</script>

and this is the input

\[ \hat{x^2} x^2\]
\[ \overline{x^2} x^2 \]
\[ \frac{x^2}{x^2} \]
\[ a_{x^2}a^{x^2} \]