Fix #7609. Type should not be mutated.
Fix #7609. Type should not be mutated.

IntelLabs/numba,seibert/numba,seibert/numba,seibert/numba,numba/numba,numba/numba,numba/numba,numba/numba,cpcloud/numba,IntelLabs/numba,seibert/numba,IntelLabs/numba,cpcloud/numba,cpcloud/numba,cpcloud/numba,numba/numba,IntelLabs/numba,IntelLabs/numba,cpcloud/numba,seibert/numba