[clang] [Clang] suppress deprecated field warnings in implicit special-member functions (PR #147400)

[Corentin Jabot via cfe-commits]

================
@@ -547,6 +547,15 @@ static void DoEmitAvailabilityWarning(Sema &S, AvailabilityResult K,
     return;
   }
   case AR_Deprecated:
+    // Suppress -Wdeprecated-declarations in purely implicit special-member functions.
+    if (auto *MD = dyn_cast_if_present<CXXMethodDecl>(S.getCurFunctionDecl());
+        MD && MD->isImplicit() && MD->isDefaulted() &&
+        (isa<CXXConstructorDecl, CXXDestructorDecl>(MD) ||
+        MD->isCopyAssignmentOperator() ||
+        MD->isMoveAssignmentOperator())) {
+    return;
+    }
+
----------------
cor3ntin wrote:

This can be simplified to


```suggestion
    // Suppress -Wdeprecated-declarations in implicit functions.
    if (auto *FD = dyn_cast_if_present<FunctionDeck>(S.getCurFunctionDecl());
        FD && FD->isImplicit())
          return; 

```

https://github.com/llvm/llvm-project/pull/147400