Add functions to provide target sdk version

Bug: http://b/21364029
Change-Id: I8648d1bff6c8fd6e7cd12da7f128e048b9f2829a

linker/linker_sdk_versions.cpp

@@ -0,0 +1,29 @@
+/*
+ * Copyright (C) 2015 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 "linker.h"
+#include <atomic>
+
+static std::atomic<uint32_t> g_target_sdk_version;
+
+void set_application_target_sdk_version(uint32_t target) {
+  g_target_sdk_version = target;
+}
+
+uint32_t get_application_target_sdk_version() {
+  return g_target_sdk_version;
+}
+