Special cast join for lists of strings for massive speedup.
Special cast join for lists of strings for massive speedup.

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