Bug

[Matthew Fluet]

The problem is with Time.toSeconds.  The Basis Library states:
       val toSeconds : time -> LargeInt.int
and also
"The type FixedInt.int is the largest fixed precision integer supported,
while the type LargeInt.int is the largest integer supported. If an
implementation provides the IntInf structure, then the type LargeInt.int
is the same as IntInf.int."

So, you're getting back an IntInf, not an Int32.  I guess the simplest
solution is to use an Int32.fromLarge cast.

(You'll probably also need to change the Test module, as MLton is taking
less than a second to do the test.)