We're rolling out new SLua Alpha sims to Aditi, with quite a large number of changes!

* Experimental changes to the Luau garbage collector to make garbage collection much faster.

* Update the underlying Luau version we use to 0.686

* Change how VM interrupts work so that triggering a metamethod after calling a particularly long-running function no longer triggers a "failed to perform mandatory yield" error

* Make garbage collection more aggressive as scripts near their memory limit, reducing the likelihood of unexpected out-of-memory errors when making repeated large allocations.

* Make and friends actually return a number that makes sense.

* Sundry bugfixes