OpenCL API loading should be redesigned #691
Description
At the moment, the loading of the OpenCL API relies on a homemade wrangler ("CLEW") that is largely obsolete (2009).
This wrangler:
- is not maintained
- hard-codes the API search paths, in a list established 15 years ago, and may therefore be limited in finding this API
- may be unstable, especially if the API is not found
- does not take into account the different versions of OpenCL that have been released since its creation
A standard mechanism (OpenCL headers, ICD loader), maintained by Khronos, now exists to fulfil this function.
The wrangler should be replaced by this standard mechanism.