Remove docs for non-existent parameters in `rustc_expand`
Remove docs for non-existent parameters in `rustc_expand`
aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,graydon/rust,graydon/rust