PNaCl Dynamic Linking: Added portable dependencies to shared objects.

tests/pnacl_dynamic_loading/dependencies_test.c

+/*
+ * Copyright 2016 The Native Client Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include <stdio.h>
+
+/*
+ * These functions would typically be declared in a shared header file, but for
+ * testing convenience, they are defined here.
+ */
+int get_module_a_var();
+int get_module_b_var();
+int get_module_c_var();
+
+/*
+ * The loader should only need to load "dependencies_test", and the dependencies
+ * should by loaded automatically by the pll_loader.
+ *
+ * | dependencies_test (depends on libc and test_pll_c)
+ *   | libc
+ *     * No dependencies
+ *   | test_pll_c (depends on test_pll_a and test_pll_b)
+ *     | test_pll_a
+ *       * No dependencies
+ *     | test_pll_b (depends on test_pll_a)
+ *       | test_pll_a
+ *         * No dependencies
+ */
+
+int main(int argc, char *argv[]) {
+  printf("%d\n", get_module_a_var());
+  printf("%d\n", get_module_b_var());
+  printf("%d\n", get_module_c_var());
+  return 0;
+}