Rollup merge of rust-lang#142194 - bjorn3:less_unstable_features, r=jieyouxu

Remove all unused feature gates from the compiler

Author: workingjubilee

compiler/rustc_ast_lowering/src/lib.rs

@@ -33,9 +33,7 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
 #![doc(rust_logo)]
-#![feature(assert_matches)]
 #![feature(box_patterns)]
-#![feature(exact_size_is_empty)]
 #![feature(if_let_guard)]
 #![feature(rustdoc_internals)]
 // tidy-alphabetical-end

compiler/rustc_builtin_macros/src/lib.rs

@@ -15,7 +15,6 @@
 #![feature(proc_macro_internals)]
 #![feature(proc_macro_quote)]
 #![feature(rustdoc_internals)]
-#![feature(string_from_utf8_lossy_owned)]
 #![feature(try_blocks)]
 #![recursion_limit = "256"]
 // tidy-alphabetical-end

compiler/rustc_codegen_gcc/src/lib.rs

@@ -16,7 +16,7 @@
 #![allow(internal_features)]
 #![doc(rust_logo)]
 #![feature(rustdoc_internals)]
-#![feature(rustc_private, decl_macro, never_type, trusted_len)]
+#![feature(rustc_private)]
 #![allow(broken_intra_doc_links)]
 #![recursion_limit = "256"]
 #![warn(rust_2018_idioms)]

compiler/rustc_codegen_llvm/src/lib.rs

@@ -9,7 +9,6 @@
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
-#![feature(exact_size_is_empty)]
 #![feature(extern_types)]
 #![feature(file_buffered)]
 #![feature(if_let_guard)]

compiler/rustc_data_structures/src/lib.rs

@@ -25,7 +25,6 @@
 #![feature(dropck_eyepatch)]
 #![feature(extend_one)]
 #![feature(file_buffered)]
-#![feature(macro_metavar_expr)]
 #![feature(map_try_insert)]
 #![feature(min_specialization)]
 #![feature(negative_impls)]

compiler/rustc_errors/src/lib.rs

@@ -15,12 +15,10 @@
 #![feature(box_patterns)]
 #![feature(default_field_values)]
 #![feature(error_reporter)]
-#![feature(if_let_guard)]
 #![feature(negative_impls)]
 #![feature(never_type)]
 #![feature(rustc_attrs)]
 #![feature(rustdoc_internals)]
-#![feature(trait_alias)]
 #![feature(try_blocks)]
 #![feature(yeet_expr)]
 // tidy-alphabetical-end

compiler/rustc_expand/src/lib.rs

@@ -6,7 +6,6 @@
 #![feature(associated_type_defaults)]
 #![feature(if_let_guard)]
 #![feature(macro_metavar_expr)]
-#![feature(map_try_insert)]
 #![feature(proc_macro_diagnostic)]
 #![feature(proc_macro_internals)]
 #![feature(rustdoc_internals)]

compiler/rustc_fluent_macro/src/lib.rs

@@ -4,7 +4,6 @@
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(proc_macro_diagnostic)]
-#![feature(proc_macro_span)]
 #![feature(rustdoc_internals)]
 #![feature(track_path)]
 // tidy-alphabetical-end

compiler/rustc_hir/src/lib.rs

@@ -5,7 +5,6 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
 #![feature(associated_type_defaults)]
-#![feature(box_patterns)]
 #![feature(closure_track_caller)]
 #![feature(debug_closure_helpers)]
 #![feature(exhaustive_patterns)]

compiler/rustc_hir_typeck/src/lib.rs

@@ -1,13 +1,11 @@
 // tidy-alphabetical-start
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
-#![feature(array_windows)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(if_let_guard)]
 #![feature(iter_intersperse)]
 #![feature(never_type)]
-#![feature(try_blocks)]
 // tidy-alphabetical-end
 
 mod _match;