load and store functions are not implemented for vec class now.

If it is needed to pass the same option from driver to both host and device compilers, then it must be added two-times - see clang/lib/Driver/ToolChains/Clang.cpp, for example:
4124:CmdArgs.push_back("-fsycl");
...
6150:CmdArgs.push_back("-fsycl");

This is quite error prone and inconvenient - should be automated: option placed in one place, driver does the duplication itself.

Just an FYI whilst I was trawling through the ROCm GitHub page:

https://rocmdocs.amd.com/en/latest/Programming_Guides/Programming-Guides.html#

The cl_ types are not needed in general, however they should still be kept in the OpenCL C interop sample code.

Turn on -fstrict-aliasing -Wstrict-aliasing.