Load libraries in breadth-first order

This patch fixes the problem with symbol search order
  for dlsym(RTLD_DEFAULT/RTLD_NEXT, .) by loading libraries
  and ld_preloads in correct order.

Bug: https://code.google.com/p/android/issues/detail?id=74255
Attempt: 2

(cherry picked from commit 14669a939d)

Change-Id: Id87540c96a2242220967b6fa5d84ddcd829e2b97

tests/libs/dlopen_testlib_answer.cpp

@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+extern "C" int dlopen_test_get_answer() {
+  return __ANSWER;
+}
+
+#ifdef __ANSWER2
+extern "C" int dlopen_test_get_answer2() {
+  return __ANSWER2;
+}
+#endif