Implementation of SymbolicEquivSet:
Implementation of SymbolicEquivSet:

* enable equivalence of ranges/slices
* reason about equivalence of simple arithmetic like + and -
* support extra shape for SetItem nodes, which is not a variable assignment.

stuartarchibald/numba,stonebig/numba,seibert/numba,stuartarchibald/numba,numba/numba,numba/numba,IntelLabs/numba,IntelLabs/numba,numba/numba,stuartarchibald/numba,stuartarchibald/numba,gmarkall/numba,sklam/numba,gmarkall/numba,cpcloud/numba,numba/numba,cpcloud/numba,sklam/numba,jriehl/numba,seibert/numba,cpcloud/numba,sklam/numba,jriehl/numba,stonebig/numba,seibert/numba,gmarkall/numba,stonebig/numba,sklam/numba,jriehl/numba,numba/numba,gmarkall/numba,stonebig/numba,seibert/numba,sklam/numba,IntelLabs/numba,jriehl/numba,cpcloud/numba,seibert/numba,cpcloud/numba,IntelLabs/numba,gmarkall/numba,stonebig/numba,stuartarchibald/numba,jriehl/numba,IntelLabs/numba