New methods to check for under-/overflow in the SMT API

Summary: Added methods to check for under-/overflow in additions, subtractions, signed divisions/modulus, negations, and multiplications.

Reviewers: ddcc, gou4shi1

Reviewed By: ddcc, gou4shi1

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59796

llvm-svn: 357088