Move subst_and_normalize_erasing_regions into normalize_erasing_regions.rs so that it's not

weirdly on it's own within the codegen module.

Author: skinnyBat

src/librustc/traits/codegen/mod.rs

@@ -5,7 +5,6 @@
 #[allow(dead_code)]
 pub mod auto_trait;
 mod chalk_fulfill;
-pub mod codegen;
 mod coherence;
 mod engine;
 pub mod error_reporting;

src/librustc/traits/mod.rs

@@ -8,6 +8,7 @@
 //! within. (This underlying query is what is cached.)
 
 use crate::ty::fold::{TypeFoldable, TypeFolder};
+use crate::ty::subst::{Subst, SubstsRef};
 use crate::ty::{self, Ty, TyCtxt};
 
 impl<'tcx> TyCtxt<'tcx> {
@@ -40,6 +41,29 @@ impl<'tcx> TyCtxt<'tcx> {
         }
     }
 
+    /// Monomorphizes a type from the AST by first applying the
+    /// in-scope substitutions and then normalizing any associated
+    /// types.
+    pub fn subst_and_normalize_erasing_regions<T>(
+        self,
+        param_substs: SubstsRef<'tcx>,
+        param_env: ty::ParamEnv<'tcx>,
+        value: &T,
+    ) -> T
+    where
+        T: TypeFoldable<'tcx>,
+    {
+        debug!(
+            "subst_and_normalize_erasing_regions(\
+             param_substs={:?}, \
+             value={:?}, \
+             param_env={:?})",
+            param_substs, value, param_env,
+        );
+        let substituted = value.subst(self, param_substs);
+        self.normalize_erasing_regions(param_env, substituted)
+    }
+
     /// If you have a `Binder<T>`, you can do this to strip out the
     /// late-bound regions and then normalize the result, yielding up
     /// a `T` (with regions erased). This is appropriate when the