Fix node destructuring for DefinedNode extension

To make this polymorphic with other method dispatch nodes, we need
to do some custom destructuring.

Before:

```
defined_node.node_parts
```

After:

```
defined_node.node_parts
```

CHANGELOG.md

@@ -10,7 +10,7 @@
 
 * [#6763](https://github.com/rubocop-hq/rubocop/pull/6763): Fix false positives in range literals for `Style/MethodCallWithArgsParentheses` `omit_parentheses`. ([@gsamokovarov]][])
 * [#6748](https://github.com/rubocop-hq/rubocop/issues/6748): Fix `Style/RaiseArgs` auto-correction breaking in contexts that require parentheses. ([@drenmi][])
-* [#6751](https://github.com/rubocop-hq/rubocop/issues/6751): Prevent `Style/OneLineConditional` from breaking on `retry` keyword. ([@drenmi][])
+* [#6751](https://github.com/rubocop-hq/rubocop/issues/6751): Prevent `Style/OneLineConditional` from breaking on `retry` and `break` keywords. ([@drenmi][])
 
 ### Changes
 

lib/rubocop/ast/node/defined_node.rb

@@ -8,6 +8,10 @@ module AST
     class DefinedNode < Node
       include ParameterizedNode
       include MethodDispatchNode
+
+      def node_parts
+        [nil, :defined?, *to_a]
+      end
     end
   end
 end

spec/rubocop/ast/defined_node_spec.rb

@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+RSpec.describe RuboCop::AST::DefinedNode do
+  let(:defined_node) { parse_source(source).ast }
+
+  describe '.new' do
+    context 'with a defined? node' do
+      let(:source) { 'defined? :foo' }
+
+      it { expect(defined_node.is_a?(described_class)).to be(true) }
+    end
+  end
+
+  describe '#receiver' do
+    let(:source) { 'defined? :foo' }
+
+    it { expect(defined_node.receiver).to eq(nil) }
+  end
+
+  describe '#method_name' do
+    let(:source) { 'defined? :foo' }
+
+    it { expect(defined_node.method_name).to eq(:defined?) }
+  end
+
+  describe '#arguments' do
+    let(:source) { 'defined? :foo' }
+
+    it { expect(defined_node.arguments.size).to eq(1) }
+    it { expect(defined_node.arguments).to all(be_sym_type) }
+  end
+end