Make `CompInfo::inner_vars` use `VarId` instead of `ItemId`
Make `CompInfo::inner_vars` use `VarId` instead of `ItemId`

rust-lang/rust-bindgen,emilio/rust-bindgen,emilio/rust-bindgen,rust-lang/rust-bindgen,emilio/rust-bindgen,rust-lang/rust-bindgen,emilio/rust-bindgen,emilio/rust-bindgen,rust-lang/rust-bindgen