rustc_expand: remove some redundant #[allow(rustc::untranslatable_diagnostic)]

compiler/rustc_expand/src/base.rs

@@ -1398,8 +1398,6 @@ fn pretty_printing_compatibility_hack(item: &Item, sess: &Session) {
         };
 
         if crate_matches {
-            // FIXME: make this translatable
-            #[allow(rustc::untranslatable_diagnostic)]
             sess.dcx().emit_fatal(errors::ProcMacroBackCompat {
                 crate_name: "rental".to_string(),
                 fixed_version: "0.5.6".to_string(),

compiler/rustc_expand/src/expand.rs

@@ -1876,7 +1876,6 @@ fn take_first_attr(
 
     // Detect use of feature-gated or invalid attributes on macro invocations
     // since they will not be detected after macro expansion.
-    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn check_attributes(&self, attrs: &[ast::Attribute], call: &ast::MacCall) {
         let features = self.cx.ecfg.features;
         let mut attrs = attrs.iter().peekable();