Add cache line size bit

arch/x86_64/include/bits/cpu.h

@@ -5,3 +5,5 @@
 static inline void arch_cpu_pause() {
     asm volatile("pause");
 }
+
+#define ARCH_CACHE_LINE_SIZE 64

include/arch/cpu.h

@@ -3,3 +3,6 @@
 #pragma once
 
 #include <bits/cpu.h>
+#include <stddef.h>
+
+constexpr size_t CACHE_LINE_SIZE = ARCH_CACHE_LINE_SIZE;