Rollup merge of #120693 - nnethercote:invert-diagnostic-lints, r=davidtwco

Invert diagnostic lints.

That is, change `diagnostic_outside_of_impl` and `untranslatable_diagnostic` from `allow` to `deny`, because more than half of the compiler has been converted to use translated diagnostics.

This commit removes more `deny` attributes than it adds `allow` attributes, which proves that this change is warranted.

r? ````@davidtwco````

compiler/rustc_middle/src/lib.rs

@@ -58,8 +58,10 @@
 #![feature(const_option)]
 #![feature(ptr_alignment_type)]
 #![feature(macro_metavar_expr)]
-#![allow(rustc::potential_query_instability)]
 #![allow(internal_features)]
+#![allow(rustc::potential_query_instability)]
+#![allow(rustc::diagnostic_outside_of_impl)]
+#![allow(rustc::untranslatable_diagnostic)]
 
 #[macro_use]
 extern crate bitflags;