ci: Add scripts to install DPClang in Linux jobs

.gitlab/.gitignore

@@ -7,6 +7,7 @@
 /appimagetool
 /bcc*
 /cmake*
+/dpclang
 /emsdk
 /fastbuild
 /iar

.gitlab/ci/dpclang-env.sh

@@ -0,0 +1,4 @@
+.gitlab/ci/dpclang.sh
+export PATH="$PWD/.gitlab/dpclang/bin:$PATH"
+export LD_LIBRARY_PATH="$PWD/.gitlab/dpclang/lib${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH}"
+dpclang --version

.gitlab/ci/dpclang.sh

@@ -0,0 +1,28 @@
+#!/bin/sh
+
+set -e
+
+baseurl="https://github.com/intel/llvm/releases/download/nightly-2026-10-11/$tarball"
+
+case "$(uname -s)-$(uname -m)" in
+    Linux-x86_64)
+        tarball="sycl_linux.tar.gz"
+        shatool="sha256sum"
+        sha256sum="5b0ed70b8c8ad551462c932caaf9377e8cae3cc67dbe14772d119eefe8e9e394"
+        ;;
+    *)
+        echo "Unrecognized platform $(uname -s)-$(uname -m)"
+        exit 1
+        ;;
+esac
+readonly shatool
+readonly sha256sum
+
+cd .gitlab
+
+echo "$sha256sum  $tarball" > dpclang.sha256sum
+curl -OL "$baseurl/$tarball"
+$shatool --check dpclang.sha256sum
+mkdir dpclang
+tar -C dpclang -xzf "$tarball"
+rm "$tarball" dpclang.sha256sum