clear ref-counted locals vars when out of scope

[mmoskal]

For example:

if (...) {
  let x = "a" + "b"
  ...
  // implict 'x = null' here
}

This can free significant amount of memory, especially if 'x' happen to be outside of any function.

[abchatra]

@mmoskal is this still valid?

[mmoskal]

Yes. It requires some live variable analysis. We could also re-use global and local variable slots. It's not critical but certainly in the nice-to-have category.