[Feature request]: Backport Lua `table.pack`, `table.unpack`, `table.move` and if possible `rawlen` and `coroutine.isyieldable`

[ccuser44]

Newer versions of Lua have the functions table.pack, table.unpack and table.move.

table.pack and table.unpack fix an error with unpack(tbl) and {...} which makes them not be able to work with nil arguments.
table.move makes copying elements from tables easier and more performant.

It would be great if these functions were backported. LuaJIT and many other Lua implementations already backport them and often times for compatibility Lua scripts add them manually if they don't exist.

Also if possible the functions coroutine.isyieldable and rawlen should be added.
rawlen simply bypasses __len methamethod to get the raw lenght.
coroutine.isyieldable tells if a couroutine can be yielded which is very helpfull to preventing errors.

[ccuser44]

Bump this is still an issue