Add test for contextual error msg
Add test for contextual error msg

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