Remove `Rvalue::Ref` handling from `HasMutInterior`
Remove `Rvalue::Ref` handling from `HasMutInterior`

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