fix: add slotFlags for implicit default slots

[KaelWD]

🤔 What is the nature of this change?

• New feature
• Fix bug
• Style optimization
• Code style optimization
• Performance optimization
• Build optimization
• Refactor code or style
• Test related
• Other

🔗 Related Issue

mentioned in #541

💡 Background or solution

Results in the same output for

<Comp>
  <div />
</Comp>

and

<Comp>
  { () => <div /> }
</Comp>

and

<Comp>
  {{ default: () => <div /> }}
</Comp>

📝 Changelog

Language	Changelog
🇺🇸 English
🇨🇳 Chinese

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[KaelWD]

Too aggressive, the existing rule already breaks certain object slots.