TF-M: Adds LLVM Clang toolchain

LLVM Clang v18.1.3 added to jammy-amd64-tf-m-build

Change-Id: I8b9fac52979dd5917fd4b4454fe892e411acdd71
Signed-off-by: Matthew Dalzell <matthew.dalzell@arm.com>
diff --git a/jammy-amd64-tf-m-build/tf-dependencies.install b/jammy-amd64-tf-m-build/tf-dependencies.install
index 2471ea3..d3735bc 100755
--- a/jammy-amd64-tf-m-build/tf-dependencies.install
+++ b/jammy-amd64-tf-m-build/tf-dependencies.install
@@ -49,3 +49,9 @@
 mkdir -p /tmp/armclang-6.21
 tar -xf /tmp/ARMCompiler6.21_standalone_linux-x86_64.tar.gz -C /tmp/armclang-6.21
 /tmp/armclang-6.21/install_x86_64.sh --no-interactive --i-agree-to-the-contained-eula -d ${ARMCLANG_6_21_DIR}
+
+# Install LLVM Clang v18.1.3 toolchain to CLANG_18_1_3_DIR
+mkdir -p ${CLANG_18_1_3_DIR}
+curl --create-dirs -fsSLo /tmp/LLVM-ET-Arm-18.1.3-Linux-x86_64.tar.xz \
+  https://github.com/ARM-software/LLVM-embedded-toolchain-for-Arm/releases/download/release-18.1.3/LLVM-ET-Arm-18.1.3-Linux-x86_64.tar.xz
+tar -xf /tmp/LLVM-ET-Arm-18.1.3-Linux-x86_64.tar.xz -C ${CLANG_18_1_3_DIR} --strip-components=1
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