If an argument on a Setup line starts with `$', treat it as a library,
but only if it does not end in a known suffix.
diff --git a/Modules/makesetup b/Modules/makesetup
index 35294c0..0f2de4b 100755
--- a/Modules/makesetup
+++ b/Modules/makesetup
@@ -130,6 +130,7 @@
 			*.[cC])		srcs="$srcs $arg";;
 			*.cc)		srcs="$srcs $arg";;
 			*.c++)		srcs="$srcs $arg";;
+			\$*)		libs="$libs $arg";;
 			*.*)		echo 1>&2 "bad word $arg in $line"
 					exit 1;;
 			[a-zA-Z_]*)	mods="$mods $arg";;