Enable __cxa_atexit && __cxa_finalize for linker

 This allows adding destructors to classes used
 for global variables.

Change-Id: I5e1cd63fe3bf8f66de88cc4f7437cafb350f49b5
diff --git a/linker/linked_list.h b/linker/linked_list.h
index 8096e62..e51eb9c 100644
--- a/linker/linked_list.h
+++ b/linker/linked_list.h
@@ -32,6 +32,9 @@
 class LinkedList {
  public:
   LinkedList() : head_(nullptr), tail_(nullptr) {}
+  ~LinkedList() {
+    clear();
+  }
 
   void push_front(T* const element) {
     LinkedListEntry<T>* new_entry = Allocator::alloc();