Rangeanalysis: Simplify Guards integration.

[aschackmull]

The Range Analysis library uses the second (_v2) Java Guards implication logic layer. This implementation detail is leaking all over, so this PR cleans that up by changing the interface to use the controls predicates that are closed under any suitable implication logic, and Java can then simply instantiate it with the proper guards layer without requiring the range analysis to know about implies_v2.
A small semantic effect is that "bound reasons" are now reported as the original comparison rather than the implied guard:

b = x < bound; // R1
...
if (b) { // R2
  use(x); // A
}

The reason for the bound on x at A is now reported as R1 instead of R2. I don't expect this to make much difference in practice.

[hvitved]

Looks plausible to me.