only try to suggest for try trait_ref

Author: csmoe

src/libcore/ops/try.rs

@@ -25,6 +25,7 @@
     )
 )]
 #[doc(alias = "?")]
+#[cfg_attr(not(bootstrap), lang = "try")]
 pub trait Try {
     /// The type of this value when viewed as successful.
     #[unstable(feature = "try_trait", issue = "42327")]

src/librustc_hir/lang_items.rs

@@ -256,4 +256,6 @@ language_item_table! {
     AlignOffsetLangItem,         "align_offset",       align_offset_fn,         Target::Fn;
 
     TerminationTraitLangItem,    "termination",        termination,             Target::Trait;
+
+    TryTraitLangItem,            "try",                try_trait,               Target::Trait;
 }

src/librustc_trait_selection/traits/error_reporting/mod.rs

@@ -402,7 +402,11 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
                         self.suggest_remove_reference(&obligation, &mut err, &trait_ref);
                         self.suggest_semicolon_removal(&obligation, &mut err, span, &trait_ref);
                         self.note_version_mismatch(&mut err, &trait_ref);
-                        self.suggest_await_before_try(&mut err, &obligation, &trait_ref, span);
+
+                        if Some(trait_ref.def_id()) == tcx.lang_items().try_trait() {
+                            self.suggest_await_before_try(&mut err, &obligation, &trait_ref, span);
+                        }
+
                         if self.suggest_impl_trait(&mut err, span, &obligation, &trait_ref) {
                             err.emit();
                             return;