Another unused feature fix

Author: bjorn3

example/mini_core_hello_world.rs

@@ -1,4 +1,5 @@
-#![feature(no_core, lang_items, never_type, linkage, extern_types, thread_local, repr_simd)]
+#![feature(no_core, lang_items, never_type, extern_types, thread_local, repr_simd)]
+#![cfg_attr(not(any(jit, target_vendor = "apple", windows)), feature(linkage))]
 #![no_core]
 #![allow(dead_code, non_camel_case_types, internal_features)]
 

example/std_example.rs

@@ -1,11 +1,4 @@
-#![feature(
-    core_intrinsics,
-    coroutines,
-    coroutine_trait,
-    repr_simd,
-    tuple_trait,
-    unboxed_closures
-)]
+#![feature(core_intrinsics, coroutines, coroutine_trait, repr_simd, tuple_trait, unboxed_closures)]
 #![allow(internal_features)]
 
 #[cfg(target_arch = "x86_64")]