IRT: Replace __attribute__((constructor)) with explicit call in _start()

src/untrusted/irt/irt_core_entry.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 <unistd.h>
-
-#include "native_client/src/shared/platform/nacl_log.h"
-#include "native_client/src/shared/srpc/nacl_srpc.h"
-
-/*
- * This is declared as weak because plugin_main_nacl.cc on the
- * Chromium side has a copy of IrtInit().
- * TODO(mseaborn): Remove IrtInit() from there and use this copy.
- */
-__attribute__((weak))
-int IrtInit(void) {
-  static int initialized = 0;
-  if (initialized) {
-    return 0;
-  }
-  if (!NaClSrpcModuleInit()) {
-    return 1;
-  }
-  NaClLogModuleInit();  /* Enable NaClLog'ing used by CHECK(). */
-  initialized = 1;
-  return 0;
-}
-
-static __attribute__((constructor)) void CallIrtInit(void) {
-  if (IrtInit()) {
-    static const char fatal_msg[] =
-        "irt initialization (IRTInit) failed.\n";
-    write(2, fatal_msg, sizeof(fatal_msg) - 1);
-    _exit(-1);
-  }
-}