Add a workflow to install nightly intel/llvm + drivers

[oleksandr-pavlyk]

Build dpctl with Open Source DPC++ toolchain.

1. Download and unpack nightly build of SYCL bundle
2. Download and unpack OpenCL CPU driver
3. Download and unpack OpenCL FPGA emulator
4. Download and unpack oneAPI TBB
5. Set-up LD_LIBRARY_PATH and PATH, CPATH
6. Set-up OCL_ICD_FILENAMES so that SYCL OpenCL plug-in knows what library to load
7. Build dpctl and run pytest.

[coveralls]

Coverage remained the same at 74.413% when pulling f6de191 on build-with-os-llvm-sycl into 112b6be on master.

[diptorupd]

We can cache these downloaded copies to speed up the workflow.

[oleksandr-pavlyk]

This would be great. I just need to know where to look for an example. GTest installation was being cached, so I will look there.

[diptorupd]

I see couple of issues here: Where are you checking if the cache is hit? I do not think caching the sycl-bundle repo based on all files in it is going to work. We need to ascertain if the cached folder is the one we want to use.

I suggest the following:
a) Create a conf file inside sycl-bundle that stores the SHA of the nightly that was used by the workflow previously.
b) Hash the sycl-bundle folder as before to ensure we have all the needed files.
c) Use the following git command (I found using internet search) to get the SHA of the latest nightly:

git -c 'versionsort.suffix=-' ls-remote --tags --sort='v:refname' git@github.com:intel/llvm.git| tail --lines=1 | awk '{print $1}'

Then check if a cached entry exists

     - name: Download nightly and components
       if: steps.cache-sycl-bundle.outputs.cache-hit != 'true'

Also check if the SHA matches. (I do not know how to do that)

[diptorupd]

You do not need a conf file. As we are storing the cloned repo we might as well run git tag | sort -V | tail -1 and compare the SHA with what the command I pasted returns.

[diptorupd]

You also need to check if the NIGHLY_TAG matches with the cached bundle_id.