Add a unit test for syscall(2).

Change-Id: Ic7d9735d46711af93c3a1747de7b2eb8cebea094
diff --git a/tests/sys_syscall_test.cpp b/tests/sys_syscall_test.cpp
new file mode 100644
index 0000000..9c5e350
--- /dev/null
+++ b/tests/sys_syscall_test.cpp
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) 2013 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 <gtest/gtest.h>
+
+#include <sys/syscall.h>
+
+TEST(unistd, syscall) {
+  ASSERT_EQ(getpid(), syscall(SYS_getpid));
+}