Update other doc.
Update other doc.

Value was renamed to Operand in https://github.com/rust-lang/rust/commit/ad2de8b4ee099916113b7b3577ac86857b1568be
ScalarPair to Slice in https://github.com/rust-lang/rust/commit/fe50b4eb1d6f7a31c53798bca3d0fa2b0670fa3d

Not familiar enough with rustc's source to know if the comment is even still applicable.
graydon/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,graydon/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust