Patch for C++ style comments

["Dan East" <dan@...>]

  I hope I am not perceived as Lua heretic for this.  :)  Here is a very
simple patch that allows C++ style comments // and /* */.  My game
engine has a config file system (separate from the lua scripting) that
uses C++ comments.  My content creators have already complained about
having to use two different syntaxes so I added the other style comments
to Lua.  This does not break the existing Lua comment style - they are
both available after this patch.

  Add this case statement to the switch block in llex.c:luaX_lex()
(around line 386):

      //Dan East: support for // and /* */ style comments
      case '/':
        next(LS);
        if (LS->current == '/') {
          while (LS->current != '\n' && LS->current != EOZ)
            next(LS);
          continue;
        } else if (LS->current == '*') {
          next(LS);
          while (LS->current != EOZ) {
            if (LS->current == '*') {
              next(LS);
              if (LS->current == '/') {
                next(LS);
                break;
              }
            }
            next(LS);
          }
          continue;
        } else
          return '/';