Potential patch for Lua-5.1.2 bug #4

["Jim Whitehead II" <jnwhiteh@...>]

The recursive coroutine/stack overflow bug that's listed on the Lua
website [http://www.lua.org/bugs.html#5.1.2-4] currently doesn't have
a patch listed and instead suggests that the right thing to do might
be moving the nCcalls counter to the global state.  It seems there was
discussion about there being issues with that in a multi-threaded
environment.

I'm currently using the following patch that approaches the problem in
a slightly different manner, and I'm wondering if there are any
obvious reasons why this isn't a good way to patch the issue (or if
there's something that's been missed entirely).

The patch can be found here: http://pastebin.ca/797346

The author would appreciate any feedback you can provide.

- Jim