llvm

f4ed132f - [SYCL] vec abi changes behind -fpreview-breaking-changes flag (#11697)

[SYCL] vec abi changes behind -fpreview-breaking-changes flag (#11697) sycl::vec was updated earlier to be SYCL 2020 conformant. But those were ABI breaking changes, and the decision has been made to put those changes behind the -fpreview-breaking-changes / __INTEL_PREVIEW_BREAKING_CHANGES flag/macro. This PR restores the old sycl::vec implementation and puts the new conforming one behind the flag/macro.