add couple list utils

list-split and list-join

tests/utils.scm

@@ -0,0 +1,22 @@
+(test-group "utils"
+
+  (test
+   '((1) (2) (3))
+   (list-split '(1 * 2 * 3) '*))
+
+  (test
+   '((1 2 3))
+   (list-split '(1 2 3) '*))
+
+  (test
+   '(() (1) (2) (3) ())
+   (list-split '(* 1 * 2 * 3 *) '*))
+
+  (test
+   '((const) (const struct something))
+   (list-split '(const * const struct something) '*))
+
+  (test
+   '(1 * 2 * 3)
+   (list-join '(1 2 3) '*))
+)