handle cfg bootstrap on compiler and miri

Signed-off-by: onur-ozkan <work@onurozkan.dev>

compiler/rustc_data_structures/src/lib.rs

@@ -10,6 +10,8 @@
 #![allow(internal_features)]
 #![allow(rustc::default_hash_types)]
 #![allow(rustc::potential_query_instability)]
+#![cfg_attr(bootstrap, feature(cfg_match))]
+#![cfg_attr(not(bootstrap), feature(cfg_select))]
 #![deny(unsafe_op_in_unsafe_fn)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
@@ -19,7 +21,6 @@
 #![feature(ascii_char_variants)]
 #![feature(assert_matches)]
 #![feature(auto_traits)]
-#![feature(cfg_select)]
 #![feature(core_intrinsics)]
 #![feature(dropck_eyepatch)]
 #![feature(extend_one)]