fixes #15122 (#15301)

tests/arc/theavy_recursion.nim

@@ -0,0 +1,43 @@
+discard """
+  output: "yay"
+  cmd: "nim c --gc:arc $file"
+"""
+
+# bug #15122
+
+import tables
+
+type
+  BENodeKind* = enum
+    tkEof,
+    tkBytes,
+    tkList,
+    tkDict
+
+  BENode* = object
+    case kind: BENodeKind
+    of tkBytes: strVal: string
+    of tkList: listVal: seq[BENode]
+    of tkDict: dictVal*: Table[string, BENode]
+    else:
+      discard
+
+proc unused(s: string): BENode =
+  # bad:
+  result = BENode(kind: tkBytes, strVal: "abc")
+
+proc main =
+  var data = {
+    "examples": {
+      "values": BENode(
+        kind: tkList,
+        listVal: @[BENode(kind: tkBytes, strVal: "test")]
+      )
+    }.toTable()
+  }.toTable()
+
+  # For ARC listVal is empty for some reason
+  doAssert data["examples"]["values"].listVal[0].strVal == "test"
+
+main()
+echo "yay"