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_lint/src/internal.rs

@@ -345,7 +345,7 @@ declare_tool_lint! {
     ///
     /// More details on translatable diagnostics can be found [here](https://rustc-dev-guide.rust-lang.org/diagnostics/translation.html).
     pub rustc::UNTRANSLATABLE_DIAGNOSTIC,
-    Allow,
+    Deny,
     "prevent creation of diagnostics which cannot be translated",
     report_in_external_macro: true
 }
@@ -357,7 +357,7 @@ declare_tool_lint! {
     ///
     /// More details on diagnostics implementations can be found [here](https://rustc-dev-guide.rust-lang.org/diagnostics/diagnostic-structs.html).
     pub rustc::DIAGNOSTIC_OUTSIDE_OF_IMPL,
-    Allow,
+    Deny,
     "prevent creation of diagnostics outside of `IntoDiagnostic`/`AddToDiagnostic` impls",
     report_in_external_macro: true
 }

compiler/rustc_lint/src/lib.rs

@@ -37,8 +37,6 @@
 #![cfg_attr(not(bootstrap), feature(trait_upcasting))]
 #![feature(min_specialization)]
 #![feature(rustc_attrs)]
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 #![allow(internal_features)]
 
 #[macro_use]

compiler/rustc_lint/src/lints.rs

@@ -1,5 +1,6 @@
-#![allow(rustc::untranslatable_diagnostic)]
 #![allow(rustc::diagnostic_outside_of_impl)]
+#![allow(rustc::untranslatable_diagnostic)]
+
 use std::num::NonZeroU32;
 
 use crate::errors::RequestedLevel;