[clang] [Clang] [C++26] Implement P2573R2: `= delete("should have a reason");` (PR #86526)

[via cfe-commits]

================
@@ -2484,6 +2498,9 @@ class FunctionDecl : public DeclaratorDecl,
 
   void setDeletedAsWritten(bool D = true) { FunctionDeclBits.IsDeleted = D; }
 
+  /// Only valid if isDeletedAsWritten() returns true.
+  void setDeletedMessage(StringLiteral *Message);
+
----------------
cor3ntin wrote:

Yes, I would prefer (my argument is that there is no scenario in which we would call setDeletedMessage without first calling setDeletedAsWritten, and we always have the information available.

https://github.com/llvm/llvm-project/pull/86526