Remove unnecessary or invalid feature attributes

src/libstd/lib.rs

@@ -250,17 +250,13 @@
 #![feature(cfg_target_thread_local)]
 #![feature(cfg_target_vendor)]
 #![feature(char_error_internals)]
-#![feature(char_internals)]
-#![feature(collections_range)]
 #![feature(compiler_builtins_lib)]
 #![feature(const_fn)]
 #![feature(core_intrinsics)]
 #![feature(dropck_eyepatch)]
 #![feature(exact_size_is_empty)]
 #![feature(external_doc)]
-#![feature(fs_read_write)]
 #![feature(fixed_size_array)]
-#![feature(float_from_str_radix)]
 #![feature(fn_traits)]
 #![feature(fnbox)]
 #![feature(futures_api)]
@@ -268,7 +264,6 @@
 #![feature(hashmap_internals)]
 #![feature(int_error_internals)]
 #![feature(integer_atomics)]
-#![feature(into_cow)]
 #![feature(lang_items)]
 #![feature(libc)]
 #![feature(link_args)]
@@ -277,34 +272,25 @@
 #![feature(needs_panic_runtime)]
 #![feature(never_type)]
 #![feature(exhaustive_patterns)]
-#![feature(num_bits_bytes)]
-#![feature(old_wrapping)]
 #![feature(on_unimplemented)]
-#![feature(oom)]
 #![feature(optin_builtin_traits)]
 #![feature(panic_internals)]
 #![feature(panic_unwind)]
-#![feature(peek)]
 #![feature(pin)]
-#![feature(placement_new_protocol)]
 #![feature(prelude_import)]
 #![feature(ptr_internals)]
-#![feature(rand)]
 #![feature(raw)]
 #![feature(rustc_attrs)]
 #![feature(std_internals)]
 #![feature(stdsimd)]
 #![feature(shrink_to)]
-#![feature(slice_bytes)]
 #![feature(slice_concat_ext)]
 #![feature(slice_internals)]
 #![feature(slice_patterns)]
 #![feature(staged_api)]
 #![feature(stmt_expr_attributes)]
-#![feature(str_char)]
 #![feature(str_internals)]
-#![feature(str_utf16)]
-#![feature(test, rustc_private)]
+#![feature(rustc_private)]
 #![feature(thread_local)]
 #![feature(toowned_clone_into)]
 #![feature(try_from)]
@@ -313,7 +299,6 @@
 #![feature(untagged_unions)]
 #![feature(unwind_attributes)]
 #![feature(use_extern_macros)]
-#![feature(vec_push_all)]
 #![feature(doc_cfg)]
 #![feature(doc_masked)]
 #![feature(doc_spotlight)]
@@ -321,7 +306,6 @@
 #![cfg_attr(windows, feature(used))]
 #![feature(doc_alias)]
 #![feature(doc_keyword)]
-#![feature(float_internals)]
 #![feature(panic_info_message)]
 #![feature(panic_implementation)]