[LLDB] Avoid a warning about an unused static variable

[mstorsjo]

Summary

The variable is unused on windows.

lldb/tools/lldb-server/lldb-gdbserver.cpp

static struct option g_long_options[] = {
     {"reverse-connect", no_argument, nullptr,
      'R'}, // Specifies that llgs attaches to the client address:port rather
            // than llgs listening for a connection from address on port.
     {"setsid", no_argument, nullptr,
      'S'}, // Call setsid() to make llgs run in its own session.
     {"fd", required_argument, nullptr, 'F'},
     {nullptr, 0, nullptr, 0}};
 
+#ifndef _WIN32
 // Watch for signals
 static int g_sighup_received_count = 0;
 
-#ifndef _WIN32
 static void sighup_handler(MainLoopBase &mainloop) {
   ++g_sighup_received_count;
 
   Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PROCESS));
   LLDB_LOGF(log, "lldb-server:%s swallowing SIGHUP (receive count=%d)",
             __FUNCTION__, g_sighup_received_count);
 
   if (g_sighup_received_count >= 2)