Reimplement the arena

example/arena.c

@@ -9,13 +9,13 @@ typedef struct {
 
 int main(void)
 {
-    Arena *arena = arena_make(sizeof(int));
-    defer { arena_destroy(arena); }
+    Arena arena = gebs_arena_get(4*1024);
+    defer { arena_destroy(&arena); }
 
     Ints ints = {0};
-    defer { list_free_alloc(arena, &ints); }
-    for (size_t i = 0; i < 1000; i++) {
-        list_append_alloc(arena, &ints, i);
+    for (size_t i = 0; i < 100; i++) {
+        list_append_alloc(&arena, &ints, i);
+        gebs_arena_reset(&arena);
     }
     for (size_t i = 0; i < ints.count; i++) {
         printf("%zu\n", i);