Simplify `cast_ptr_alignment` `pointer::casr` case
Simplify `cast_ptr_alignment` `pointer::casr` case

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