Make A1.allocate() zero returned memory

src/hulk/hurl/a1.d

@@ -7,6 +7,7 @@ import hulk.hurl;
 import hulk.hippo;
 import hulk.util;
 import hulk.pagetable;
+import hulk.memory;
 
 /**
  * The A1 memory allocator is a one-shot memory allocator for kernel memory
@@ -48,6 +49,8 @@ struct A1
             current_limit += PAGE_SIZE;
         }
 
+        memset64(cast(void *)address, 0, size / 8);
+
         return cast(void *)address;
     }