This is about Intel® System Studio: OpenCL™ Tools component 2020 and Intel® SDK for OpenCL™ Applications 2020
Those are versions are not a good choice for developing OpenCL applications with Visual Studio.
Unfortunately, this is not spelled out clearly in any "Documentation", "Developer Guides" and "Release Notes" documents. The picture only gets clear when pulling all information together from various documents:
Intel is trying to phase out OpenCL development.
This is nowhere noted on any of the web pages, except that you can see that OpenCL is suddenly missing in some of the latest pages (e.g. OneAPI/System Studio) and there's only DPC++ being mentioned, but that's not cross-platform like OpenCL (it might be cross-platform on paper, but in reality it's not).
All related tools in Visual Studio have been removed. OpenCL projects still compile and there's syntax highlighting for .cl files, but not much more is left.
I think the best option right now, is to use Intel System Studio 2019 instead. I Hope this helps anybody else getting lost by the lack of clear statements in that matter.
PS: Intel, please document this clearly
Thank you, @softworkz, for your interest in OpenCL(tm) on Intel(r) products. We appreciate you pointing out the discrepancies in the documentation. I'll follow up with the teams managing these products. Rest assured Intel(r) plans continued support for OpenCL(tm) on their GPUs in the foreseeable future. This can be seen in the vigorous activity and community engagement on our open source compute runtime, https://github.com/intel/compute-runtime, which contains support for OpenCL(tm). The open source driver currently supports Linux but the core is shared with our Windows driver. Apologies for any confusion related to the documentation. We'll clean it up. We're extremely busy with many exciting features and products in the pipeline and this miscommunication fell through the cracks.
GPGPU SW Architect