Move `error` from top_stmts and top_stmt to stmt

By this change, syntax error is recovered smaller units.
In the case below, "DEFN :bar" is same level with "CLASS :Foo"
now.

```
module Z
  class Foo
    foo.
  end

  def bar
  end
end
```

[Feature #19013]

1 files changed, 3 insertions, 0 deletions

diff --git a/node.c b/node.c
index 483e7fa8fb..c7469151ec 100644
--- a/node.c
+++ b/node.c
@@ -1098,6 +1098,9 @@ dump_node(VALUE buf, VALUE indent, int comment, const NODE * node)
             F_NODE(nd_pkwrestarg, "keyword rest argument");
         }
         return;
+      case NODE_ERROR:
+        ANN("Broken input recovered by Error Tolerant mode");
+        return;
 
       case NODE_ARGS_AUX:
       case NODE_LAST: