Ryan Scott authored Dec 09, 2020 and Marge Bot committed Dec 11, 2020

This Note has severely bitrotted, as it has no references anywhere in the
codebase, and none of the functions that it mentions exist anymore. Let's just
delete this. While I was in town, I deleted some outdated comments from
`checkFamPatBinders` of a similar caliber.

Fixes #19008.

[ci skip]