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

[Alexey Bader via cfe-commits]

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@@ -14,9 +14,11 @@
 #define LLVM_CLANG_SEMA_SEMASYCL_H
 
 #include "clang/AST/Decl.h"
+#include "clang/AST/DeclBase.h"
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bader wrote:

I'm okay with that.
It just looks strange to add forward declaration for `Decl` class when full declaration is included with `#include "clang/AST/Decl.h"`. Probably the cleaner solution would be to drop forward declaration of `Decl` and add it in the follow-up patch.
Anyway, this is a minor comment and should not block the merge.

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