[MIPS] Implementation of sel_ldr for MIPS architecture.

src/trusted/service_runtime/linux/mips/sel_segments.c

+/*
+ * Copyright 2012 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 <stdint.h>
+#include "native_client/src/trusted/service_runtime/sel_util.h"
+
+uint32_t NaClGetStackPtr(void) {
+  uint32_t sp;
+
+  asm("move %0, $sp" : "=r" (sp));
+
+  return sp;
+}
+
+uint32_t NaClGetGlobalPtr(void) {
+  uint32_t gp;
+
+  asm("move %0, $gp" : "=r" (gp));
+
+  return gp;
+}
+