Return NULL when aligning forward if ptr is NULL

mem/src/util/mem_utils.c

@@ -2,10 +2,15 @@
 #include "aliases.h"
 #include <assert.h>
 #include <stdbool.h>
+#include <stdlib.h>
 
 internal bool is_power_of_two(u64 num) { return (num & (num - 1)) == 0; }
 
 void *mem_util_align_forward(void *ptr, u64 alignment) {
+  if (!ptr) {
+    return NULL;
+  }
+
   assert(is_power_of_two(alignment));
 
   uptr p = (uptr)ptr;