CI-clvk: compile with SPIRV_IL OFF (#1338)

It will avoid breakage when LLVM-SPIRV-TRANSLATOR from clvk does not
match the llvm version in clspv

kokoro/scripts/linux/build-clvk.sh

@@ -89,6 +89,7 @@ cmake -DPYTHON_EXECUTABLE:FILEPATH=/usr/bin/python3 -GNinja -DCMAKE_BUILD_TYPE=$
   -DCLVK_CLSPV_ONLINE_COMPILER=ON -DCLSPV_SOURCE_DIR="$SRC" \
   -DCLVK_ENABLE_ASSERTIONS=ON \
   -DCLVK_VULKAN_IMPLEMENTATION=custom -DVulkan_INCLUDE_DIRS=${VULKAN_HEADERS_SRC}/include -DVulkan_LIBRARIES="$VULKAN_LOADER_BUILD/loader/libvulkan.so" \
+  -DCLVK_ENABLE_SPIRV_IL=OFF \
   "$CLVK_SRC"
 ninja
 echo $(date): Clvk build completed.