Add diagnostic translation lints to crates that don't emit them

compiler/rustc_hir_pretty/src/lib.rs

@@ -1,4 +1,6 @@
 #![recursion_limit = "256"]
+#![deny(rustc::untranslatable_diagnostic)]
+#![deny(rustc::diagnostic_outside_of_impl)]
 
 use rustc_ast as ast;
 use rustc_ast::util::parser::{self, AssocOp, Fixity};