message: gdb-remote: fix the build on Windows
  Windows does not have a definition for `mode_t`.  Include the appropriate
  header.
diff: #include "lldb/Utility/ArchSpec.h"
  #include "lldb/Utility/StreamGDBRemote.h"
  #include "lldb/Utility/StructuredData.h"
  +#if defined(_WIN32)
  +#include "lldb/Host/windows/PosixApi.h"
  +#endif
  #include "llvm/ADT/Optional.h"
  #include "llvm/Support/VersionTuple.h"
  