message: util.h: Document FileCommit function
diff: @@ -56,6 +56,11 @@ bool error(const char* fmt, const Args&... args)
  }
  void PrintExceptionContinue(const std::exception *pex, const char* pszThread);
  +
  +/**
  + * Ensure file contents are fully committed to disk, using a platform-specific
  + * feature analogous to fsync().
  + */
  bool FileCommit(FILE *file);
  bool TruncateFile(FILE *file, unsigned int length);
  int RaiseFileDescriptorLimit(int nMinFD);
  