Delete old re-exports from rustc_smir

This approach didn't seem to work well.

compiler/rustc_smir/src/lib.rs

@@ -13,7 +13,3 @@
 #![cfg_attr(not(feature = "default"), feature(rustc_private))]
 #![deny(rustc::untranslatable_diagnostic)]
 #![deny(rustc::diagnostic_outside_of_impl)]
-
-pub mod mir;
-
-pub mod very_unstable;

compiler/rustc_smir/src/mir.rs

@@ -1,10 +0,0 @@
-pub use crate::very_unstable::hir::ImplicitSelfKind;
-pub use crate::very_unstable::middle::mir::{
-    visit::MutVisitor, AggregateKind, AssertKind, BasicBlock, BasicBlockData, BinOp, BindingForm,
-    BlockTailInfo, Body, BorrowKind, CastKind, ClearCrossCrate, Constant, ConstantKind,
-    CopyNonOverlapping, Coverage, FakeReadCause, Field, GeneratorInfo, InlineAsmOperand, Local,
-    LocalDecl, LocalInfo, LocalKind, Location, MirPhase, MirSource, NullOp, Operand, Place,
-    PlaceRef, ProjectionElem, ProjectionKind, Promoted, RetagKind, Rvalue, Safety, SourceInfo,
-    SourceScope, SourceScopeData, SourceScopeLocalData, Statement, StatementKind, UnOp,
-    UserTypeProjection, UserTypeProjections, VarBindingForm, VarDebugInfo, VarDebugInfoContents,
-};

compiler/rustc_smir/src/very_unstable.rs

@@ -1,27 +0,0 @@
-//! This module reexports various crates and modules from unstable rustc APIs.
-//! Add anything you need here and it will get slowly transferred to a stable API.
-//! Only use rustc_smir in your dependencies and use the reexports here instead of
-//! directly referring to the unstable crates.
-
-macro_rules! crates {
-    ($($rustc_name:ident -> $name:ident,)*) => {
-        $(
-            #[cfg(not(feature = "default"))]
-            pub extern crate $rustc_name as $name;
-            #[cfg(feature = "default")]
-            pub use $rustc_name as $name;
-        )*
-    }
-}
-
-crates! {
-    rustc_borrowck -> borrowck,
-    rustc_driver -> driver,
-    rustc_hir -> hir,
-    rustc_interface -> interface,
-    rustc_middle -> middle,
-    rustc_mir_dataflow -> dataflow,
-    rustc_mir_transform -> transform,
-    rustc_serialize -> serialize,
-    rustc_trait_selection -> trait_selection,
-}