[clang] [clang] Split up `SemaDeclAttr.cpp` (PR #93966)

[Vlad Serebrennikov via cfe-commits]

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@@ -32,6 +32,7 @@
 #include "clang/Basic/Specifiers.h"
 #include "clang/Sema/DeclSpec.h"
 #include "clang/Sema/Ownership.h"
+#include "clang/Sema/ParsedAttr.h"
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Endilll wrote:

Yeah, I totally forgot about forward decls while preparing this PR. I fixed that for the things added in this PR, leaving the rest for later.

https://github.com/llvm/llvm-project/pull/93966