=== Stack Management ===
A stack, rather than being a seperate Tuple object, is simply a variable
size array located inside a MethodContext (meaning MethodContext objects
are variable size).

When running code, the stack of the current MethodContext is stored into
directly, without running any write barrier. This means though, that if a
MethodContext is old, and a new object is stored into it's stack, the
MethodContext must be check at young GC collect time.

A simple solution is to check if the MethodContext is old before it's
activated. If it is, add it to the remember set if it's not already.

Any Task method that touches the stack of a context not active needs
to also check and run the write barrier.


