[sanitizers] Add missing definition

[oontvoo]

Summary

Fix breakages from https://reviews.llvm.org/D90811

http://lab.llvm.org:8011/#/builders/37/builds/471/steps/8/logs/stdio

[oontvoo]

rebase

compiler-rt/lib/sanitizer_common/sanitizer_common_nolibc.cpp

 //===-- sanitizer_common_nolibc.cpp ---------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // This file contains stubs for libc function to facilitate optional use of
 // libc in no-libcdep sources.
 //===----------------------------------------------------------------------===//
 
-#include "sanitizer_platform.h"
 #include "sanitizer_common.h"
+#include "sanitizer_flags.h"
 #include "sanitizer_libc.h"
+#include "sanitizer_platform.h"
 
 namespace __sanitizer {
 
 // The Windows implementations of these functions use the win32 API directly,
 // bypassing libc.
 #if !SANITIZER_WINDOWS
 #if SANITIZER_LINUX
 void LogMessageOnPrintf(const char *str) {}
 #endif
 void WriteToSyslog(const char *buffer) {}
 void Abort() { internal__exit(1); }
 void SleepForSeconds(int seconds) { internal_sleep(seconds); }
 #endif // !SANITIZER_WINDOWS
 
 #if !SANITIZER_WINDOWS && !SANITIZER_MAC
 void ListOfModules::init() {}
+void InitializePlatformCommonFlags(CommonFlags *cf) {}
 #endif
 
 }  // namespace __sanitizer