Cleanup historical stability comments
Cleanup historical stability comments

These weren't removed by ccbcc720a679ae76155a8 most likely by accident,
let's clean them up now.

graydon/rust,aidancully/rust,aidancully/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,graydon/rust,graydon/rust,graydon/rust