Ensure defaults are normalized after application

Thanks to @eddyb for bringing this bug to my attention.

Author: jroesch

src/librustc_typeck/check/mod.rs

@@ -1876,9 +1876,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             let _ = self.infcx().commit_if_ok(|_: &infer::CombinedSnapshot| {
                 for &(ref ty, ref default) in &has_user_default {
                     let default = default.clone();
+                    let normalized_default = self.inh.normalize_associated_types_in(codemap::DUMMY_SP, 0, &default.ty);
                     match infer::mk_eqty(self.infcx(), false,
                                          infer::Misc(codemap::DUMMY_SP), // default.origin_span),
-                                         ty, default.ty) {
+                                         ty, normalized_default) {
                         Ok(()) => {}
                         Err(_) => {
                             conflicts.push((*ty, default));
@@ -1975,9 +1976,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // reporting for more then one conflict.
         for &(ref ty, ref default) in tys_with_defaults {
             let default = default.clone();
+            let normalized_default = self.inh.normalize_associated_types_in(codemap::DUMMY_SP, 0, &default.ty);
             match infer::mk_eqty(self.infcx(), false,
                                  infer::Misc(codemap::DUMMY_SP), // default.origin_span),
-                                 ty, default.ty) {
+                                 ty, normalized_default) {
                 Ok(()) => {}
                 Err(_) => {
                     result = Some(default);