Create the CaseBuilder monad alias.
Add ReaderT to CaseBuilder.
Add getInaccessibleArgs.
Bring erasure info to the case tree builder.
Extend argsToAlt to return a quadruple.
Adjust code around argsToAlt.
More changes to argsToAlt.
Implement accessible+inaccessible splitting.
Disable PAny for repeated patvars.
Purify toPats.
Comment clarification.
Simplify argsToAlt.
Merge pull request #1360 from ziman/case-elab-erasure

Make case elaboration respect dots