small refactor and cleanup

tests/override_dup_compile_time.sl

@@ -0,0 +1,28 @@
+import ../stdlib/stdlib.sl
+import ../stdlib/io.sl
+
+: dup
+    6
+;
+compile-only
+
+: emit-overridden
+    "dup" use-l2-ct
+    42
+    dup
+    int>string
+    nil
+    token-from-lexeme
+    list-new
+    swap
+    list-append
+    inject-tokens
+;
+immediate
+compile-only
+
+: main
+    emit-overridden
+    puti cr
+    0
+;