Make sure that the transitive constraint optimization does not cause
WHERE clause terms to be disabled prematurely.  We are unable to find a test
case that fails because of this, but it seems prudent to make this
preventative change nevertheless.
Deterministically initialize the PRNG used as a tie-breaker in the ANALYZE
command, so that the analysis is always the same given the same database.
This simplifies testing.
Merge trunk fixes into the unlikely-func branch.