BasicConstraintManager:

BasicConstraintManager:
- Fix nonsensical logic in AssumeSymGE. When comparing 'sym >= constant' and the
  constant is the maximum integer value, add the constraint that 'sym ==
  constant' when the path is deemed feasible.  All other cases are feasible.
- Improve AssumeSymGT. When comparing 'sym > constant' and constant is the
  maximum integer value we know the path is infeasible.
- Add test case for this enhancement to AssumeSymGT.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@60490 91177308-0d34-0410-b5e6-96231b3b80d8