mesa: disable llvmpipe except on select architectures

srcpkgs/mesa/template

@@ -28,6 +28,14 @@ if [ "$XBPS_TARGET_LIBC" = "musl" ]; then
 	configure_args+=" -Duse-elf-tls=false"
 fi
 
+# only use llvmpipe on targets where it's supported and reliable
+# especially on big endian it's all kinds of broken, and e.g. on
+# 32-bit powerpc it does not work at all, so fall back to softpipe
+case "$XBPS_TARGET_MACHINE" in
+	x86_64*|aarch64*|ppc64le*|arm*) ;;
+	*) configure_args+=" -Ddraw-use-llvm=false" ;;
+esac
+
 # Set subpackages manually to set proper rdeps in 32bit pkgs.
 subpackages="libglapi libgbm libOSMesa"