Represent 'unit' as C 'int'; change pattern match compilation to avoid 'goto'; change Postgres prepared statement compilation to make life easier for the GCC escape analysis; all this in support of better tail call optimization

type t

val create : string -> t
val out : t -> string
val frob : t -> string -> t
val print : transaction unit

val foo : transaction unit
val bar : string -> transaction unit

val transactional : transaction unit