jammy-amd64-tf-a-build-next: add clang-18

Add clang18.1.18 to the staging area to test its
use in the TF-A CI.

This is needed to upgrade hafnium build to clang-18.

Signed-off-by: J-Alves <joao.alves@arm.com>
Change-Id: I62e52a55b0e1a2b8e0a971ac68a4244c7ed72429
diff --git a/jammy-amd64-tf-a-build-next/tf-dependencies.install b/jammy-amd64-tf-a-build-next/tf-dependencies.install
index dc817db..271b5b9 100644
--- a/jammy-amd64-tf-a-build-next/tf-dependencies.install
+++ b/jammy-amd64-tf-a-build-next/tf-dependencies.install
@@ -44,6 +44,11 @@
   https://releases.linaro.org/components/toolchain/binaries/6.2-2016.11/aarch64-linux-gnu/gcc-linaro-6.2.1-2016.11-x86_64_aarch64-linux-gnu.tar.xz
 tar -Jxf /tmp/gcc-linaro-x86_64_aarch64-linux-gnu.tar.xz -C ${TOOLS_DIR}
 
+# Install LLVM Clang toolchain (clang)
+curl --connect-timeout 5 --retry 5 --create-dirs -fsSLo /tmp/clang+llvm-18.1.8-x86_64-linux-gnu-ubuntu-18.04.tar.xz \
+  https://github.com/llvm/llvm-project/releases/download/llvmorg-18.1.8/clang+llvm-18.1.8-x86_64-linux-gnu-ubuntu-18.04.tar.xz
+tar -xf /tmp/clang+llvm-18.1.8-x86_64-linux-gnu-ubuntu-18.04.tar.xz -C ${TOOLS_DIR} --strip-components=1
+
 # Install Arm Clang 6.18 toolchain (armclang)
 mkdir -p /tmp/armclang-6.18
 tar -xf /tmp/ARMCompiler6.18_standalone_linux-x86_64.tar.gz -C /tmp/armclang-6.18