Remove #![feature(let_chains)] from library and src/librustdoc

Author: est31

compiler/rustc_pattern_analysis/src/lib.rs

@@ -6,7 +6,6 @@
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
 #![allow(unused_crate_dependencies)]
-#![cfg_attr(all(feature = "rustc", bootstrap), feature(let_chains))]
 // tidy-alphabetical-end
 
 pub mod constructor;

library/core/src/lib.rs

@@ -158,7 +158,6 @@
 #![feature(intra_doc_pointers)]
 #![feature(intrinsics)]
 #![feature(lang_items)]
-#![feature(let_chains)]
 #![feature(link_llvm_intrinsics)]
 #![feature(macro_metavar_expr)]
 #![feature(marker_trait_attr)]

library/std/src/lib.rs

@@ -304,7 +304,6 @@
 #![feature(iter_advance_by)]
 #![feature(iter_next_chunk)]
 #![feature(lang_items)]
-#![feature(let_chains)]
 #![feature(link_cfg)]
 #![feature(linkage)]
 #![feature(macro_metavar_expr_concat)]

src/librustdoc/lib.rs

@@ -11,7 +11,6 @@
 #![feature(if_let_guard)]
 #![feature(impl_trait_in_assoc_type)]
 #![feature(iter_intersperse)]
-#![feature(let_chains)]
 #![feature(never_type)]
 #![feature(round_char_boundary)]
 #![feature(test)]