[libcxx-commits] [libcxx] [NFC][libc++] Moves ios_base's forward declaration. (PR #88027)

[A. Jiang via libcxx-commits]

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@@ -25,7 +25,6 @@ template<>            struct char_traits<wchar_t>;
 
 template<class T>     class allocator;
 
-class ios_base;
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frederick-vs-ja wrote:

I guess it should change to match [[iosfwd.syn]](https://eel.is/c++draft/iosfwd.syn).

https://github.com/llvm/llvm-project/pull/88027