[clang] [AMDGPU][Clang] Support for type inferring extended image builtins for AMDGPU (PR #164358)

[Shilei Tian via cfe-commits]

shiltian wrote:

I'm not sure about the new added `e`. It is very confusing.

> It's ok for me. I wish we didn't have to add the `e` case, but I do not see an easy way out.

Even with the OpenCL `cl_khr_fp16` extension, the FP16 is still just a storage class?

https://github.com/llvm/llvm-project/pull/164358