PTX runQ on Nvidia-free hardware

**Is your feature request related to a problem? Please describe.**
`runQ` variant of PTX runners cannot build on non-target machines, i.e. a machine w/o Nvidia GPU or drivers installed.

**Describe the solution you'd like**
For the `runQ` path, we must not compile PTX through the module compilation API exposed by `libcuda` and instead use the CLI utilities such as `ptxas` and LLVM utils.

It would also be necessary to provide a way to specify the target information to `runQ` style TH functions, since that information is typically gleaned from `libcuda`.