dev-util/spirv-llvm-translator: support new OpenCL block representation

dev-util/spirv-llvm-translator: support new OpenCL block representation

Without this patch, offline compilation of certain kernels used by
dev-libs/intel-neo unit tests fails with "LLVM ERROR: unknown argument
number for an object"; some real-world kernels would presumably be
affected as well.

The patch has been retrieved from
https://github.com/intel/opencl-clang/blob/ocl-open-80/patches/spirv/0001-Update-LowerOpenCL-pass-to-handle-new-blocks-represn.patch
(commit 912a9cc8d30b773372ce58d4fc17bf38fd388692 i.e. latest version as of
2019-05-02).

See-Also: https://github.com/intel/compute-runtime/issues/156
Signed-off-by: Marek Szuba <marecki@gentoo.org>
Package-Manager: Portage-2.3.62, Repoman-2.3.11