Cleanup `render_stability_since_raw` to remove code duplication
Cleanup `render_stability_since_raw` to remove code duplication

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