Support for printing vectors
Introduce a varrec struct
Convert normalize-lambdas phase to use varrec structs

And the simplify phase doesn't touch varrecs.
Convert resolve-variables phase to use varrec structs
Convert classify-variables phase to use varrec structs
Convert collect-closures phase to use varrec structs
Convert fill-closures phase to use varrec structs
Convert codegen to use varrec structs
Convert the varrec mode attribute into a field
Convert the varrec state attribute into a misc field
Convert varrec access attribute into a field
Convert the varrec origin attribute into a field
Convert the varrec closure-stack attribute to use the misc field
A lamba's self varrec is by definition not written
Convert the varrec lambda attribute into a field
Convert the boxed varrec attribute into a field
Convert the source varrec attribute into a field
Convert the varrec fixups attribute to use the misc field
Convert the varrec index attribute into a field

And reuse it for the label attribute on top-level varrecs.
All varrec attributes are gone