Fix OpenCL with older Sympy and pyopencl versions
I'm using sympy and pyopencl from the Ubuntu 18.04 repositories and these changes were required to make the OpenCL tests pass on an Nvidia machine. AMD doesn't work, see #15 (closed).
I'm using sympy and pyopencl from the Ubuntu 18.04 repositories and these changes were required to make the OpenCL tests pass on an Nvidia machine. AMD doesn't work, see #15 (closed).