Loopify denote

[FintanH]

@sellout noticed that we were calling denote at each call of isNormalized meaning we traverse the tree superfluously.

This just uses the same technique as normalizeWith where we denote once and then check for normalization.

fwiw: This shaved 20s or so off some private benchmarks :)

Edit: 60s actually 😄

[Gabriella439]

Good catch! Yeah, this is a much better way of doing it! :)