message: use intrinsics to avoid function calls within startup code
diff: @@ -9,7 +9,7 @@ use application_processor_main;
  use arch::x86_64::kernel::KERNEL_HEADER;
  use boot_processor_main;
  use config::KERNEL_STACK_SIZE;
  -use core::ptr;
  +use core::intrinsics;
  #[inline(never)]
  #[no_mangle]
  @@ -27,10 +27,10 @@ pub unsafe extern "C" fn _start() -> ! {
  // initialize stack pointer
  asm!("mov $0, %rsp; mov %rsp, %rbp"
  - :: "r"(ptr::read_volatile(&KERNEL_HEADER.current_stack_address) + KERNEL_STACK_SIZE as u64 - 0x10)
  + :: "r"(intrinsics::volatile_load(&KERNEL_HEADER.current_stack_address) + KERNEL_STACK_SIZE as u64 - 0x10)
  :: "volatile");
  - if ptr::read_volatile(&KERNEL_HEADER.cpu_online) == 0 {
  + if intrinsics::volatile_load(&KERNEL_HEADER.cpu_online) == 0 {
  boot_processor_main();
  } else {
  application_processor_main();
  