ci: bump debian image and change llvm deps to 8

v3: remove version in a few places (Michel)

Reviewed-by: Michel Dänzer <mdaenzer@redhat.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Tested-by: Marge Bot <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3805>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3805>

.gitlab-ci.yml

@@ -112,7 +112,7 @@ x86_build:
     - .debian@container-ifnot-exists
     - .container
   variables:
-    DEBIAN_TAG: &x86_build "2020-02-05"
+    DEBIAN_TAG: &x86_build "2020-02-15"
 
 .use-x86_build:
   variables:
@@ -473,7 +473,6 @@ meson-s390x:
   variables:
     CROSS: s390x
     GALLIUM_DRIVERS: "swrast"
-    LLVM_VERSION: "7"
   script:
     - dpkg -i /var/cache/apt/archives/$CROSS/*.deb
     - .gitlab-ci/meson-build.sh
@@ -484,7 +483,6 @@ meson-ppc64el:
   variables:
     CROSS: ppc64el
     GALLIUM_DRIVERS: "nouveau,radeonsi,swrast,virgl"
-    LLVM_VERSION: "8"
     VULKAN_DRIVERS: "amd"
 
 meson-mingw32-x86_64:

.gitlab-ci/container/x86_build.sh

@@ -76,6 +76,7 @@ apt-get install -y --no-remove \
       libxvmc-dev \
       libxxf86vm-dev \
       llvm-6.0-dev \
+      llvm-7-dev \
       llvm-9-dev \
       meson \
       pkg-config \
@@ -97,29 +98,22 @@ for arch in $CROSS_ARCHITECTURES; do
             libelf-dev:${arch} \
             libexpat1-dev:${arch}
 
-    if [ "$arch" = "s390x" ]; then
-        LLVM_VERSION=7
-    else
-        LLVM_VERSION=8
-    fi
-
     if [ "$arch" != "i386" ]; then
         mkdir /var/cache/apt/archives/${arch}
         apt-get install -y --no-remove \
                 libffi-dev:${arch} \
-                libllvm${LLVM_VERSION}:${arch} \
+                libllvm8:${arch} \
                 libstdc++6:${arch} \
                 libtinfo-dev:${arch} \
 
         # Download llvm-* packages, but don't install them yet, since they can
         # only be installed for one architecture at a time
         apt-get install -o Dir::Cache::archives=/var/cache/apt/archives/$arch --download-only -y --no-remove \
-            llvm-${LLVM_VERSION}-dev:${arch}
+            llvm-8-dev:${arch}
     fi
 done
 
 apt-get install -y --no-remove \
-      llvm-7-dev \
       llvm-8-dev \
 
 # for 64bit windows cross-builds