Prefix' Darwin systems are single arch, hijack Darwin7 case which assumes this setup
--- a/configure.ac+++ b/configure.ac@@ -1860,7 +1860,7 @@ if test "$enable_universal" != "no"; then
case "$host_os" in
- darwin[[0-7]].*)+ darwin**) #
# Pre-Tiger. Build only for 32-bit PowerPC; no
# need for any special compiler or linker flags.