Support for vector types with more than 4 elements

[Ardy123]

Today, opencl code that uses vector types with more than 4 elements needs to be rewritten to work around the 4 element restriction. It would be nice that even if SPIR-V doesn't support it, if code could be generate to work around that limitation... For example, a char16 is really 4 char4s (once translated to spir-v) instead of just throwing an error message..

"Vectors with more than 4 elements are not supported"

[dneto0]

Yes, this is often requested.

It has been lower on our list of priorities. See #63 (comment)

However, as this project matures this request is now closer to our planning horizon. I'll keep this request open.

[rjodinchr]

Long vector are now supported