Add a get_random_bytes() syscall to replace the SRPC-based implementation

tests/random/random_test.c

 /*
  * Copyright (c) 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 <stdio.h>
 #include <string.h>
 
 #include <nacl/nacl_random.h>
 
 #include "native_client/src/include/nacl_assert.h"
-#include "native_client/src/shared/srpc/nacl_srpc.h"
 #include "native_client/tests/inbrowser_test_runner/test_runner.h"
 
 int TestMain(void) {
-#if !TESTS_USE_IRT
-  NaClSrpcModuleInit();
-#endif
-
   int result = 0;
 
   uint8_t byte1 = 0;
   uint8_t byte2 = 0;
   size_t nread;
   int error = nacl_secure_random(&byte1, sizeof(byte1), &nread);
   if (error != 0) {
     fprintf(stderr, "get_random_bytes failed for size %u: %s\n",
             sizeof(byte1), strerror(error));
     result = 1;
@@ skipping 57 matching lines @@
    */
   int init_result = nacl_secure_random_init();
   ASSERT_EQ(init_result, 0);
 
   return result;
 }
 
 int main(void) {
   return RunTests(TestMain);
 }