Add RTLD_NOLOAD support and some related changes.

* Aligned RTLD_ values with glibc for lp64
 * dlopen supports RTLD_NOLOAD flag
 * soinfo_unload calls find_library(.., RTLD_NOLOAD)
   instead of naive find_loaded_library_by_name()
 * dlopen changed to add child to caller soinfo instead
   of somain.

Bug: https://code.google.com/p/android/issues/detail?id=64069
Change-Id: I1a65f2c34f3e0edc6d2c41a2e408b58195feb640

tests/dlopen_testlib_simple.cpp

@@ -0,0 +1,23 @@
+/*
+ * 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.
+ */
+
+#include <stdlib.h>
+
+uint32_t dlopen_testlib_taxicab_number = 1729;
+
+bool dlopen_testlib_simple_func() {
+  return true;
+}