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 be converted to use translated diagnostics.

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

compiler/rustc_log/src/lib.rs

@@ -38,9 +38,6 @@
 //! debugging, you can make changes inside those crates and quickly run main.rs
 //! to read the debug logs.
 
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
-
 use std::env::{self, VarError};
 use std::fmt::{self, Display};
 use std::io::{self, IsTerminal};