ocl: pointer-arithmetic for device-pointers #1496

Job	Run time
build-and-test (MPI=ON, OPENMP=ON, SMM=blas, openmpi)	4m 15s
build-on-opencl (OPENMP=ON, SMM=libxsmm)	8m 5s
build-on-cuda (OPENMP=ON)	8m 13s
build-and-test (MPI=ON, OPENMP=ON, SMM=blas, mpich)	3m 56s
pre-commit	1m 13s
build-and-test (MPI=ON, OPENMP=ON, SMM=libxsmm, openmpi)	4m 46s
build-on-rocm (OPENMP=ON, G2G=ON)	3m 58s
build-and-test (MPI=ON, OPENMP=ON, SMM=libxsmm, mpich)	4m 13s
build-on-rocm (OPENMP=ON, G2G=OFF)	3m 40s
build-and-test (MPI=ON, OPENMP=OFF, SMM=blas, openmpi)	9m 12s
build-and-test (MPI=ON, OPENMP=OFF, SMM=blas, mpich)	9m 39s
build-and-test (MPI=ON, OPENMP=OFF, SMM=libxsmm, openmpi)	8m 59s
build-and-test (MPI=ON, OPENMP=OFF, SMM=libxsmm, mpich)	9m 20s
build-and-test (MPI=OFF, OPENMP=ON, SMM=blas, openmpi)	5m 28s
build-and-test (MPI=OFF, OPENMP=ON, SMM=libxsmm, openmpi)	5m 14s
build-and-test (MPI=OFF, OPENMP=OFF, SMM=blas, openmpi)	3m 35s
build-and-test (MPI=OFF, OPENMP=OFF, SMM=libxsmm, openmpi)	3m 22s
Combine & check coverage.	1m 25s
	1h 38m 33s

Provide feedback