Added: arena_release implementation

src/arena.c

@@ -40,4 +40,9 @@ arena_allocate(Arena *arena, u64 size)
 internal void
 arena_release(Arena *arena)
 {
+  for (Arena *node = arena->current, *prev = 0; node != 0; node = prev)
+  {
+    prev = node->prev;
+    platform_memory_release(node, node->size);
+  }
 }