prematurely killing threads in 5.0 beta

["xenarcher <nickl@...>" <nickl@...>]

In 5.0 alpha, threads had to be killed manually with the 
lua_closethread() function. As far as I can tell, Lua had no way of 
automatically determining if a thread was dead, which is why you 
needed to manually call lua_closethread().

In 5.0 beta, it looks like Lua can now detect completed threads. The 
lua_closethread() function was removed, presumably because "dead 
thread detection" was now implemented.

My question is: since the lua_closethread() function has been removed 
in 5.0 beta, is there still a way to manually kill a thread that is 
still active?