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

sequence seq
table fred : {A : int, B : int}

task initialize = fn () =>
    setval seq 1;
    dml (INSERT INTO fred (A, B) VALUES (0, 1))