Remove #%expression in plambda.
Remove extraneous old feature of do-inst.
Make inst not do crazy splitting.
Make inst mark the #%expression.
Move from type-ascription-property to add-ann.
Remove check for type-ascription property.
Add #%expression around annotations.
Cleanup type-ascription.
Remove obsolete special casing for ann and inst.
Change ascription to annotate the #%expression.
Remove now useless type-annotation tests.
Make external check be on an #%expression.
Cleanup obsolete loop.
Split out tc-expression to a separate file.
Cleanup tc-expression.
Make do-inst work on tc-results.
Fix scoped type variables.