gitlab-ci: Enable llvmpipe in ARM build jobs

v2:
* Use LLVM 8 from buster-backports
v3:
* Use LLVM 7 again for armhf, llvmpipe is still broken there with LLVM 8

Acked-by: Eric Engestrom <eric.engestrom@intel.com>

.gitlab-ci.yml

@@ -202,14 +202,13 @@ meson-main:
       -D gallium-va=false
       -D gallium-xa=false
       -D gallium-nine=false
-      -D llvm=false
 
 .meson-arm:
   extends: .meson-cross
   image: $DEBIAN_ARM64_IMAGE
   variables:
     VULKAN_DRIVERS: freedreno
-    GALLIUM_DRIVERS: "etnaviv,freedreno,kmsro,lima,nouveau,panfrost,tegra,v3d,vc4"
+    GALLIUM_DRIVERS: "etnaviv,freedreno,kmsro,lima,nouveau,panfrost,swrast,tegra,v3d,vc4"
     EXTRA_OPTION: >
       -D I-love-half-baked-turnips=true
   needs:
@@ -221,6 +220,7 @@ meson-armhf:
   extends: .meson-arm
   variables:
     CROSS: armhf
+    LLVM_VERSION: "7"
 
 meson-arm64:
   extends:

.gitlab-ci/debian-arm64-install.sh

@@ -6,6 +6,7 @@ set -o xtrace
 ############### Install packages for building
 apt-get -y install ca-certificates
 sed -i -e 's/http:\/\/deb/https:\/\/deb/g' /etc/apt/sources.list
+echo 'deb https://deb.debian.org/debian buster-backports main' >/etc/apt/sources.list.d/backports.list
 dpkg --add-architecture armhf
 apt-get update
 apt-get -y install \
@@ -30,6 +31,8 @@ apt-get -y install \
 	libgles2-mesa-dev \
 	libpng-dev \
 	libssl-dev \
+	llvm-7-dev:armhf \
+	llvm-8-dev \
 	meson \
 	ninja-build \
 	pkg-config \