[clang] [clang][win] Define vector deleting dtor body for declared-only dtor if needed (PR #185653)

[Mariya Podchishchaeva via cfe-commits]

================
@@ -1201,6 +1202,10 @@ void CodeGenFunction::EmitNewArrayInitializer(
     EmitCXXAggrConstructorCall(Ctor, NumElements, CurPtr, CCE,
                                /*NewPointerIsChecked*/ true,
                                CCE->requiresZeroInitialization());
+    if (getContext().classNeedsVectorDeletingDestructor(Ctor->getParent())) {
+      CXXDestructorDecl *Dtor = Ctor->getParent()->getDestructor();
+      CGM.EmitGlobal(GlobalDecl(Dtor, Dtor_VectorDeleting));
----------------
Fznamznon wrote:

I would be happy to use `addDeferredDeclToEmit` directly but it is a private member of CGM. Does that make sense to make it public so it is accessible from CGF?
What I'm trying to do here is to add a deferred decl to emit for a vector deleting destructor if we just emitted a new[]. It is required because currently all deleting destructors (including vector and scalar) are emitted during emission of vtable. If constructor of the class is defined in another translation unit, no vtable will be emitted and no deleting destructors either. I actually noticed that even if I define destructor but not the constructor, call new[], no vector deleting destructor will be emitted by clang and this also seems wrong https://godbolt.org/z/5Y4vzsWEj. We just need a separate path for all vector deleting destructors that doesn't depend on the vtable. 

https://github.com/llvm/llvm-project/pull/185653