Makes marker kinds a direct reflection of the ocaml type; removes the 'variable'
and 'function' kinds.
Adds a new column to the synchronized array of markers that indicates if a
marker is a variable, a function, or something else.

similar semantics as the parameter of same name in
`add_assigns` and `add_allocates` in contracts

Into -dive-from-variables and -dive-from-alarms respectively.