librustdoc: remove unneeded #[allow]s

Author: yotamofek

src/librustdoc/lib.rs

@@ -20,9 +20,6 @@
 #![feature(type_ascription)]
 #![recursion_limit = "256"]
 #![warn(rustc::internal)]
-#![allow(clippy::collapsible_if, clippy::collapsible_else_if)]
-#![allow(rustc::diagnostic_outside_of_impl)]
-#![allow(rustc::untranslatable_diagnostic)]
 
 extern crate thin_vec;