Add __errno_location

src/unix/unikraft/mod.rs

@@ -1081,6 +1081,8 @@ extern "C" {
         flags: ::c_int,
     ) -> ::ssize_t;
 
+    pub fn __errno_location() -> *mut ::c_int;
+
     pub fn pthread_set_name_np(tid: ::pthread_t, name: *const ::c_char);
 
     pub fn pthread_condattr_getclock(