win32: Flag some unused arg warnings.

src/extras/getopt.c

@@ -359,6 +359,8 @@ static const char *
      char *const *argv;
      const char *optstring;
 {
+    (void)argc;
+    (void)argv;
     /* Start processing options with ARGV-element 1 (since ARGV-element 0
        is the program name); the sequence of previously skipped
        non-option ARGV-elements is empty.  */

src/misc/w32thread.c

@@ -373,6 +373,7 @@ void vlc_rwlock_unlock (vlc_rwlock_t *lock)
 int vlc_threadvar_create (vlc_threadvar_t *p_tls, void (*destr) (void *))
 {
 #warning FIXME: use destr() callback and stop leaking!
+
     *p_tls = TlsAlloc();
     return (*p_tls == TLS_OUT_OF_INDEXES) ? EAGAIN : 0;
 }

src/misc/win32_specific.c

@@ -47,6 +47,7 @@
  *****************************************************************************/
 void system_Init( libvlc_int_t *p_this, int *pi_argc, const char *ppsz_argv[] )
 {
+    VLC_UNUSED( p_this ); VLC_UNUSED( pi_argc ); VLC_UNUSED( ppsz_argv );
     WSADATA Data;
 
     /* Get our full path */