New pipeline: atrace on PTX #582

On the new pipeline, atrace is not implemented on the PTX platform. atrace (& friends) provide tracing like in Debug.Trace, exported from Data.Array.Accelerate.Debug.Trace. In the rewrite of the compiler, they still need to be implemented for the PTX backend.

To work on this issue, you need to work on the new pipeline of Accelerate, available via the branch new-pipeline on my fork (https://github.com/ivogabe/accelerate/tree/new-pipeline). Install cbc and clang as command line tools and add them to the PATH. Write an Accelerate program that uses atrace, and run this program on the PTX backend. You will get errors about missing implementations for atrace in certain functions, which should all be addressed for this issue.