bootstrap: also apply unused-attributes hack without deny_warnings
bootstrap: also apply unused-attributes hack without deny_warnings

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