Merge from rustc

Author: The Miri Conjob Bot

src/bin/miri.rs

@@ -2,7 +2,9 @@
 #![allow(
     clippy::manual_range_contains,
     clippy::useless_format,
-    clippy::field_reassign_with_default
+    clippy::field_reassign_with_default,
+    rustc::diagnostic_outside_of_impl,
+    rustc::untranslatable_diagnostic,
 )]
 
 extern crate rustc_data_structures;

src/lib.rs

@@ -10,7 +10,7 @@
 #![feature(nonzero_ops)]
 #![feature(let_chains)]
 #![feature(lint_reasons)]
-#![cfg_attr(not(bootstrap), feature(trait_upcasting))]
+#![feature(trait_upcasting)]
 // Configure clippy and other lints
 #![allow(
     clippy::collapsible_else_if,
@@ -33,8 +33,10 @@
     clippy::bool_to_int_with_if,
     clippy::box_default,
     clippy::needless_question_mark,
+    rustc::diagnostic_outside_of_impl,
     // We are not implementing queries here so it's fine
-    rustc::potential_query_instability
+    rustc::potential_query_instability,
+    rustc::untranslatable_diagnostic,
 )]
 #![warn(
     rust_2018_idioms,