[AD] replace xlock/xunlock with synchronized{}

[Jon Rafkind <workmin@xxxxxxxxxx>]

Would anyone be opposed to replacing all the XLOCK()/XUNLOCK() blocks in 
the x11 code of Allegro with a #define'd syntax that does the same 
thing, with preferably the same name as java's sychnronization keyword 
'synchronized' ?

Basically do this

#define synchronized for ( XLOCK(); XUNLOCK(); /**/ )

and then instead of

int _xwin_create_window(void)
{
  int result;
  XLOCK();
  result = (*_xwin_window_creator)();
  XUNLOCK();
  return result;
}

would be

int _xwin_create_window(void)
{
  int result;
  synchronized{
      result = (*_xwin_window_creator)();
   }
  return result;
}

Yes I use Java a lot these days and I find this very clean. Plus it 
would prevent the mistake of forgetting to use XUNLOCK() occasionally.