finish trait solver skeleton work

Cargo.lock

@@ -4783,6 +4783,7 @@ dependencies = [
  "rustc_middle",
  "rustc_parse_format",
  "rustc_query_system",
+ "rustc_serialize",
  "rustc_session",
  "rustc_span",
  "rustc_target",

compiler/rustc_middle/src/infer/canonical.rs

@@ -339,6 +339,12 @@ TrivialTypeTraversalAndLiftImpls! {
 }
 
 impl<'tcx> CanonicalVarValues<'tcx> {
+    /// Creates dummy var values which should not be used in a
+    /// canonical response.
+    pub fn dummy() -> CanonicalVarValues<'tcx> {
+        CanonicalVarValues { var_values: Default::default() }
+    }
+
     #[inline]
     pub fn len(&self) -> usize {
         self.var_values.len()

compiler/rustc_middle/src/ty/sty.rs

@@ -1106,17 +1106,6 @@ impl<'tcx, T> Binder<'tcx, T> {
         if self.0.has_escaping_bound_vars() { None } else { Some(self.skip_binder()) }
     }
 
-    pub fn no_bound_vars_ignoring_escaping(self, tcx: TyCtxt<'tcx>) -> Option<T>
-    where
-        T: TypeFoldable<'tcx>,
-    {
-        if !self.0.has_escaping_bound_vars() {
-            Some(self.skip_binder())
-        } else {
-            self.0.try_fold_with(&mut SkipBindersAt { index: ty::INNERMOST, tcx }).ok()
-        }
-    }
-
     /// Splits the contents into two things that share the same binder
     /// level as the original, returning two distinct binders.
     ///

compiler/rustc_trait_selection/Cargo.toml

@@ -19,6 +19,7 @@ rustc_infer = { path = "../rustc_infer" }
 rustc_lint_defs = { path = "../rustc_lint_defs" }
 rustc_macros = { path = "../rustc_macros" }
 rustc_query_system = { path = "../rustc_query_system" }
+rustc_serialize = { path = "../rustc_serialize" }
 rustc_session = { path = "../rustc_session" }
 rustc_span = { path = "../rustc_span" }
 rustc_target = { path = "../rustc_target" }

compiler/rustc_trait_selection/src/lib.rs

@@ -21,6 +21,7 @@
 #![feature(never_type)]
 #![feature(result_option_inspect)]
 #![feature(type_alias_impl_trait)]
+#![feature(min_specialization)]
 #![recursion_limit = "512"] // For rustdoc
 
 #[macro_use]