fix warning: the feature has been stable since 1.69.0-nightly and no longer requires an attribute to enable

Author: chyyuu

ch4/src/main.rs

@@ -1,7 +1,7 @@
 #![no_std]
 #![no_main]
 #![feature(naked_functions, asm_const)]
-#![feature(default_alloc_error_handler)]
+//#![feature(default_alloc_error_handler)]
 #![deny(warnings)]
 
 mod process;

ch5/src/main.rs

@@ -1,7 +1,7 @@
 #![no_std]
 #![no_main]
 #![feature(naked_functions, asm_const)]
-#![feature(default_alloc_error_handler)]
+//#![feature(default_alloc_error_handler)]
 #![deny(warnings)]
 
 mod process;

ch6/src/main.rs

@@ -1,7 +1,7 @@
 #![no_std]
 #![no_main]
 #![feature(naked_functions, asm_const)]
-#![feature(default_alloc_error_handler)]
+//#![feature(default_alloc_error_handler)]
 #![deny(warnings)]
 
 mod fs;

ch7/src/main.rs

@@ -1,8 +1,8 @@
 #![no_std]
 #![no_main]
 #![feature(naked_functions, asm_const)]
-#![feature(default_alloc_error_handler)]
-// #![deny(warnings)]
+//#![feature(default_alloc_error_handler)]
+#![deny(warnings)]
 
 mod fs;
 mod process;

ch8/src/main.rs

@@ -1,8 +1,8 @@
 #![no_std]
 #![no_main]
 #![feature(naked_functions, asm_const)]
-#![feature(default_alloc_error_handler)]
-// #![deny(warnings)]
+//#![feature(default_alloc_error_handler)]
+#![deny(warnings)]
 
 mod fs;
 mod process;