xzre_code: add count_bits

xzre_code/CMakeLists.txt

@@ -1,6 +1,7 @@
 add_library(xzre_code
 	backdoor_entry.c
 	chacha_decrypt.c
+	count_bits.c
 	count_pointers.c
 	elf_parse.c
 	elf_symbol_get_addr.c

xzre_code/count_bits.c

@@ -0,0 +1,10 @@
+/**
+ * Copyright (C) 2024 Stefano Moioli <[email protected]>
+ **/
+#include "xzre.h"
+
+u32 count_bits(u64 x){
+	u32 result;
+	for(result=0; x; ++result, x &= x-1);
+	return result;
+}