Summary:
Handle the case of
- computing the range of `[lb, ub]` where `lb` contains length path and `ub` is constant. E.g. `[a.length, 2]` would give `3` range
- simplifying `c1 +/- min(c2, a.length)` to `c1 +/- min(c2, 0)`
since the length of a collection/array is always nonnegative.
This also removes some existing FPs in tests results.
Facebook
Context: we stumbled upon this issue in ObjC results TV109717121 which is corresponding to the added test case.
Reviewed By: skcho
Differential Revision: D23648807
fbshipit-source-id: 1e89ea246