docker: Add build arg for extra packages; move opencl/libclc.

docker/build-and-push-images.sh

@@ -221,6 +221,12 @@ args_toolchain()
 			return 0
 			;;
 		clang*)
+			if test "$_epoch" -ge 15; then
+				extra="mesa-opencl-icd"
+				extra="${extra} ocl-icd-opencl-dev"
+				extra="${extra} libclc-${_epoch}-dev"
+				args="$args --build-arg extra_packages=\"${extra}\""
+			fi
 			extra_dev="clang-${_epoch}"
 			extra_dev="${extra_dev} llvm-${_epoch}"
 			extra_dev="${extra_dev} llvm-spirv-${_epoch}"

docker/ubuntu/full/Dockerfile

@@ -6,11 +6,12 @@ ARG machine
 
 FROM ${acct}/${repo}:${dist_name}-${dist_version}-base-${machine}
 
+ARG extra_packages
+
 ENV packages="\
 libgraphicsmagick-q16-3 \
 libpng16-16 \
-mesa-opencl-icd \
-ocl-icd-opencl-dev \
+${extra_packages} \
 "
 
 ENV packages_dev="\