#![deny(clippy::manual_let_else)] in some rustc modules

compiler/rustc_ast/src/lib.rs

@@ -6,6 +6,7 @@
 
 // tidy-alphabetical-start
 #![cfg_attr(bootstrap, feature(array_windows))]
+#![deny(clippy::manual_let_else)]
 #![doc(test(attr(deny(warnings), allow(internal_features))))]
 #![feature(associated_type_defaults)]
 #![feature(box_patterns)]

compiler/rustc_borrowck/src/lib.rs

@@ -2,6 +2,7 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![deny(clippy::manual_let_else)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(file_buffered)]

compiler/rustc_const_eval/src/lib.rs

@@ -1,5 +1,6 @@
 // tidy-alphabetical-start
 #![allow(rustc::diagnostic_outside_of_impl)]
+#![deny(clippy::manual_let_else)]
 #![feature(array_try_map)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]

compiler/rustc_hir/src/lib.rs

@@ -4,6 +4,7 @@
 
 // tidy-alphabetical-start
 #![cfg_attr(bootstrap, feature(debug_closure_helpers))]
+#![deny(clippy::manual_let_else)]
 #![feature(associated_type_defaults)]
 #![feature(closure_track_caller)]
 #![feature(const_default)]

compiler/rustc_hir_analysis/src/lib.rs

@@ -59,6 +59,7 @@ This API is completely unstable and subject to change.
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
 #![cfg_attr(bootstrap, feature(debug_closure_helpers))]
+#![deny(clippy::manual_let_else)]
 #![feature(assert_matches)]
 #![feature(gen_blocks)]
 #![feature(if_let_guard)]

compiler/rustc_hir_typeck/src/lib.rs

@@ -1,4 +1,5 @@
 // tidy-alphabetical-start
+#![deny(clippy::manual_let_else)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(if_let_guard)]

compiler/rustc_lint/src/lib.rs

@@ -22,6 +22,7 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
 #![cfg_attr(bootstrap, feature(array_windows))]
+#![deny(clippy::manual_let_else)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(if_let_guard)]

compiler/rustc_middle/src/lib.rs

@@ -30,6 +30,7 @@
 #![allow(rustc::direct_use_of_rustc_type_ir)]
 #![allow(rustc::untranslatable_diagnostic)]
 #![cfg_attr(bootstrap, feature(array_windows))]
+#![deny(clippy::manual_let_else)]
 #![feature(allocator_api)]
 #![feature(assert_matches)]
 #![feature(associated_type_defaults)]

compiler/rustc_next_trait_solver/src/lib.rs

@@ -8,6 +8,7 @@
 #![allow(rustc::direct_use_of_rustc_type_ir)]
 #![allow(rustc::usage_of_type_ir_inherent)]
 #![allow(rustc::usage_of_type_ir_traits)]
+#![deny(clippy::manual_let_else)]
 // tidy-alphabetical-end
 
 pub mod canonical;

compiler/rustc_resolve/src/lib.rs

@@ -10,6 +10,7 @@
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![deny(clippy::manual_let_else)]
 #![feature(arbitrary_self_types)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]