Remove some feature(debug_closure_helpers) attributes

compiler/rustc_hir/src/lib.rs

@@ -3,9 +3,9 @@
 //! [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/hir.html
 
 // tidy-alphabetical-start
+#![cfg_attr(bootstrap, feature(debug_closure_helpers))]
 #![feature(associated_type_defaults)]
 #![feature(closure_track_caller)]
-#![feature(debug_closure_helpers)]
 #![feature(exhaustive_patterns)]
 #![feature(never_type)]
 #![feature(variant_count)]

compiler/rustc_hir_analysis/src/lib.rs

@@ -59,10 +59,10 @@ This API is completely unstable and subject to change.
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(bootstrap, feature(debug_closure_helpers))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
-#![feature(debug_closure_helpers)]
 #![feature(gen_blocks)]
 #![feature(if_let_guard)]
 #![feature(iter_intersperse)]

compiler/rustc_target/src/lib.rs

@@ -9,9 +9,9 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(debug_closure_helpers))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
-#![feature(debug_closure_helpers)]
 #![feature(iter_intersperse)]
 #![feature(rustdoc_internals)]
 // tidy-alphabetical-end

src/librustdoc/lib.rs

@@ -1,4 +1,5 @@
 // tidy-alphabetical-start
+#![cfg_attr(bootstrap, feature(debug_closure_helpers))]
 #![doc(
     html_root_url = "https://doc.rust-lang.org/nightly/",
     html_playground_url = "https://play.rust-lang.org/"
@@ -7,7 +8,6 @@
 #![feature(ascii_char_variants)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
-#![feature(debug_closure_helpers)]
 #![feature(file_buffered)]
 #![feature(formatting_options)]
 #![feature(if_let_guard)]