devel/intel-graphics-compiler: note llvm10 (production) flavor cannot be exposed
llvm11 is considered experimental but llvm10 doesn't work for us:
FAILED: bin/built_ins/x64/gen12lp/bindful_aux_translation_Gen12LPlp.spv /wrkdirs/usr/ports/lang/intel-compute-runtime/work-llvm10/.build/bin/built_ins/x64/gen12lp/bindful_aux_translation_Gen12LPlp.spv
cd /wrkdirs/usr/ports/lang/intel-compute-runtime/work-llvm10/compute-runtime-21.32.20609/shared/source/built_ins/kernels && LD_LIBRARY_PATH=/wrkdirs/usr/ports/lang/intel-compute-runtime/work-llvm10/.build/bin /wrkdirs/usr/ports/lang/intel-compute-runtime/work-llvm10/.build/bin/ocloc -q -file aux_translation.builtin_kernel -spv_only -device tgllp -64 -output bindful_aux_translation -out_dir /wrkdirs/usr/ports/lang/intel-compute-runtime/work-llvm10/.build/bin/built_ins/x64/gen12lp -options -cl-kernel-arg-info
: CommandLine Error: Option 'mc-relax-all' registered more than once!
LLVM ERROR: inconsistency in registered CommandLine options