Unit tests for Lua core

["Eric Tetz" <erictetz@...>]

I was making a small change to the Lua lexer, and wanted to validate
that I've not broken anything unrelated to my change. It occurred to
me that the Lua authors must have their own set of tests -- code
that exercises every nook and cranny of the language and validates
correctness -- which they themselves run after making changes. Are
these available somewhere?

Cheers,
Eric