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

[Vlad Serebrennikov via cfe-commits]

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@@ -3825,6 +3843,115 @@ class Sema final : public SemaBase {
 
   void redelayDiagnostics(sema::DelayedDiagnosticPool &pool);
 
+  /// Diagnose mutually exclusive attributes when present on a given
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Endilll wrote:

Making functions accept reference to `SemaBase` is novel, but seem to work fine without negative consequences. I moved the whole block to `Sema/Attr.h`.

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