Bump to rust nightly-2022-01-01, feature global_asm,asm->stable

user/src/lib.rs

@@ -1,5 +1,4 @@
 #![no_std]
-#![feature(asm)]
 #![feature(linkage)]
 #![feature(panic_info_message)]
 #![feature(alloc_error_handler)]

user/src/syscall.rs

@@ -1,3 +1,5 @@
+use core::arch::asm;
+
 const SYSCALL_DUP: usize = 24;
 const SYSCALL_OPEN: usize = 56;
 const SYSCALL_CLOSE: usize = 57;