Auxiliary functions introduced in elaboration (e.g., through case splits and with clauses) now
have the same totality annotation as the function they're defined in.
Moved auxiliary function `findSetTotal` into `Context.idr` since it's
now used by `ProcessDef.idr` too.
Added a totality requirement argument to `checkClause` so that the
with-clause case could propagate it to the functions it generates in
elaboration.
Sandwhich the rhs elaboration in pattern matches with code that sets
the global, default, totality requirement to the current one, and
restores the previous default afterwards. It's a bit of a hacky way to
do it, but I don't think we have a better alternative with the current
design.