swift 下使用animationN 方法失效 ivar_getTypeEncoding 类型取不到

[Ymuyangyin]

New Issue Checklist

• [ ] I have read the Documentation
• [ ] I have searched for a similar issue in the project and found none

Issue Info

Info	Value
Platform Name	e.g. iOS / macOS
Platform Version	e.g. 12.0 / 10.14.0
TABAnimated Version	e.g. 5.0.0 / 4.4.0
Xcode Version	e.g. Xcode 11 / Xcode 10
Repro rate	e.g. all the time (100%) / sometimes x% / only once
Repro with our demo prj	e.g. does it happen with our demo project?
Demo project link	e.g. link to a demo project that highlights the issue

Issue Description and Steps

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