compiler: Wire {TyAnd,}Layout into rustc_abi

This finally unites TyAndLayout, Layout, and LayoutS into the same crate,
as one might imagine they would be placed. No functional changes.

compiler/rustc_abi/src/layout/ty.rs

@@ -6,10 +6,8 @@ use Primitive::*;
 use rustc_data_structures::intern::Interned;
 use rustc_macros::HashStable_Generic;
 
-pub mod call;
-
 // Explicitly import `Float` to avoid ambiguity with `Primitive::Float`.
-pub use rustc_abi::{Float, *};
+use crate::{Float, *};
 
 rustc_index::newtype_index! {
     /// The *source-order* index of a field in a variant.