Fix dlsym(3) to do breadth first search.

  dlsym(3) with handle != RTLD_DEFAULT|RTLD_NEXT performs
  breadth first search through the dependency tree.

Bug: 16653281
Change-Id: I017a6975d1a62abb0218a7eb59ae4deba458e324
diff --git a/linker/tests/linked_list_test.cpp b/linker/tests/linked_list_test.cpp
index 31ec7d5..b9816fa 100644
--- a/linker/tests/linked_list_test.cpp
+++ b/linker/tests/linked_list_test.cpp
@@ -95,3 +95,23 @@
   ASSERT_TRUE(free_called);
   ASSERT_EQ("", test_list_to_string(list));
 }
+
+TEST(linked_list, push_pop) {
+  test_list_t list;
+  list.push_front("b");
+  list.push_front("a");
+  ASSERT_EQ("ab", test_list_to_string(list));
+  list.push_back("c");
+  ASSERT_EQ("abc", test_list_to_string(list));
+  ASSERT_EQ("a", list.pop_front());
+  ASSERT_EQ("bc", test_list_to_string(list));
+  ASSERT_EQ("b", list.pop_front());
+  ASSERT_EQ("c", test_list_to_string(list));
+  ASSERT_EQ("c", list.pop_front());
+  ASSERT_EQ("", test_list_to_string(list));
+  ASSERT_TRUE(list.pop_front() == nullptr);
+  list.push_back("r");
+  ASSERT_EQ("r", test_list_to_string(list));
+  ASSERT_EQ("r", list.pop_front());
+  ASSERT_TRUE(list.pop_front() == nullptr);
+}