Jude Melton-Houghton

This change corrects the translation of C++ exceptions into Lua errors when using bundled PUC Lua. Without this change, the error object accessible to Lua when e.g. `get_content_id` failed would...

If they choose to do so, Minetest will still work. They will have to remove `lua_atccall`, of course. C++ errors will not be catchable from Lua, and throwing Lua errors...

It seems they already patch Minetest: https://github.com/minetest/minetest/pull/11664#issuecomment-1160547526

IMO either this PR should be merged before 5.6.0 or https://github.com/minetest/minetest/pull/11683 should be reverted until after 5.6.0 is released. Including https://github.com/minetest/minetest/pull/11683 and not this PR could lead to big issues...

Perhaps this could be added to the new 5.6.1 milestone, since it fixes a bug I introduced in 5.6.0.

I added a commit to let people build with the system's version of PUC Lua.

Even without this PR, distributors who swap in the system's Lua will find that the Lua destructor unit test fails. This test was added in 5.6.

I just ran the unit tests with [this patch](https://salsa.debian.org/games-team/minetest/-/blob/master/debian/patches/rawlua.patch) applied. As expected, both `testCxxExceptions` and `testLuaDestructors` fail.

In that case, patching in the system Lua will work just as well as it did before (that is, it will work most of the time.) Therefore, this will not...

I probably won't rebase this unless the concept is approved.