Fix relocation to look for symbols in local group

The local group is a sequence of libraries in default (breadth-first)
  order. It allows RTLD_LOCALLY loaded library to correctly relocate
  symbols within its group (see test-cases).

  Local group lookup is performed after main executable and ld_preloads.

Bug: 2643900
Bug: 15432753
Bug: 18186310

(cherry picked from commit cfa97f172d)

Change-Id: I5fa8c673f929e4652c738912c7ae078d7ec286d2

tests/libs/dlopen_check_order_dlsym_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 check_order_dlsym_get_answer() {
+  return __ANSWER;
+}
+
+#ifdef __ANSWER2
+extern "C" int check_order_dlsym_get_answer2() {
+  return __ANSWER2;
+}
+#endif