Remove unused function `lower_opt_bounds`
Remove unused function `lower_opt_bounds`

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