Simplify the stdbuild section

Author: est31

src/lib.rs

@@ -86,10 +86,8 @@
 ))]
 
 // Attributes needed when building as part of the standard library
-#![cfg_attr(feature = "stdbuild", feature(no_std, staged_api, custom_attribute, cfg_target_vendor))]
+#![cfg_attr(feature = "stdbuild", feature(staged_api, custom_attribute, cfg_target_vendor))]
 #![cfg_attr(feature = "stdbuild", feature(link_cfg, repr_packed))]
-#![cfg_attr(feature = "stdbuild", no_std)]
-#![cfg_attr(feature = "stdbuild", staged_api)]
 #![cfg_attr(feature = "stdbuild", allow(warnings))]
 #![cfg_attr(feature = "stdbuild", unstable(feature = "libc",
                                reason = "use `libc` from crates.io",