Remove unused features

compiler/rustc_data_structures/src/lib.rs

@@ -10,6 +10,7 @@
 #![allow(internal_features)]
 #![allow(rustc::default_hash_types)]
 #![allow(rustc::potential_query_instability)]
+#![cfg_attr(not(parallel_compiler), feature(cell_leak))]
 #![deny(rustc::diagnostic_outside_of_impl)]
 #![deny(rustc::untranslatable_diagnostic)]
 #![deny(unsafe_op_in_unsafe_fn)]
@@ -18,7 +19,6 @@
 #![feature(allocator_api)]
 #![feature(array_windows)]
 #![feature(auto_traits)]
-#![feature(cell_leak)]
 #![feature(cfg_match)]
 #![feature(core_intrinsics)]
 #![feature(extend_one)]