Docs reference local and exchange heap without explanation

In section 13 of the 0.6 docs the local and exchange heap are referenced without previous explanation.

Like other types in Rust, vectors can be stored on the stack, the local heap, or the exchange heap.

[thestinger]

Thanks, the tutorial shouldn't be mentioning exchange/local heap at all because it's easier to just say Owned things are sendable. It's not actually accurate that unique pointers/vectors are allocated on the exchange heap, since that's only true if they don't contain managed pointers.

It might make sense to talk about this in the language reference but... it would make even more sense to treat it as an implementation detail, covered in a separate implementation document.

[catamorphism]

The main tutorial, tasks tutorial, and borrowed pointer tutorial still mention the exchange heap. Easy cleanup task.

[graydon]

Runtime is referring to these as local and global heaps now.