For now, only reduce/reduce conflicts w/ no tie-breaking precedence
are treated as errors. The rest are dropped, because shift/reduce
conflicts are currently very common because we don't have a way
of specifying associativity along w/ precedence.
Now, instead of adding states to the lex table as they are needed
by the parse states, we iterate over the parse states after the fact
and set up their corresponding lex states. This has the nice side
effect that the lex states are in a more readable order.
