bionic-amd64-tf-m-build: Install ArmClang 6.21

Primary motivation at this time is to test is there's an improvement
re: discovered issues with ArmClang 6.18 UBL (produces binaries which
fail LAVA tests).

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
Change-Id: I52fe9d03b18b45d63ed09ebc66bf3431e38ccd62
diff --git a/bionic-amd64-tf-m-build/Dockerfile b/bionic-amd64-tf-m-build/Dockerfile
index 4478a4e..ff20d05 100644
--- a/bionic-amd64-tf-m-build/Dockerfile
+++ b/bionic-amd64-tf-m-build/Dockerfile
@@ -20,6 +20,8 @@
 ENV ARMCLANG_6_13_PATH=${ARMCLANG_6_13_DIR}/bin
 ENV ARMCLANG_6_18_DIR=${COMPILER_DIR}/armclang-6-18
 ENV ARMCLANG_6_18_PATH=${ARMCLANG_6_18_DIR}/bin
+ENV ARMCLANG_6_21_DIR=${COMPILER_DIR}/armclang-6-21
+ENV ARMCLANG_6_21_PATH=${ARMCLANG_6_21_DIR}/bin
 ENV PKG_DEPS="\
     bison \
     build-essential \
diff --git a/bionic-amd64-tf-m-build/build.sh b/bionic-amd64-tf-m-build/build.sh
index fe860b2..5b1a9a9 100755
--- a/bionic-amd64-tf-m-build/build.sh
+++ b/bionic-amd64-tf-m-build/build.sh
@@ -21,6 +21,7 @@
 # from s3://trustedfirmware-private/armclang/ by build harness).
 cp ../DS500-BN-00026-r5p0-15rel0.tar.gz .
 cp ../ARMCompiler6.18_standalone_linux-x86_64.tar.gz .
+cp ../ARMCompiler6.21_standalone_linux-x86_64.tar.gz .
 
 image=trustedfirmware/ci-${ARCHITECTURE}-${PROJECT}-ubuntu:${DISTRIBUTION}${DOCKER_SUFFIX}
 docker build --pull --tag=$image .
diff --git a/bionic-amd64-tf-m-build/tf-dependencies.install b/bionic-amd64-tf-m-build/tf-dependencies.install
index 58f24b0..8cb7d08 100755
--- a/bionic-amd64-tf-m-build/tf-dependencies.install
+++ b/bionic-amd64-tf-m-build/tf-dependencies.install
@@ -49,3 +49,7 @@
 tar -xf /tmp/ARMCompiler6.18_standalone_linux-x86_64.tar.gz -C /tmp/armclang-6.18
 /tmp/armclang-6.18/install_x86_64.sh --no-interactive --i-agree-to-the-contained-eula -d ${ARMCLANG_6_18_DIR}
 
+# Install Arm Clang v6.21 toolchain to ARMCLANG_6_21_DIR (armclang)
+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}