[clang] [Clang][Sema] Don't warn on accessing virtual base from abstract class (PR #217715)

[Yanzuo Liu via cfe-commits]

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@@ -1411,6 +1411,8 @@ struct B : public A {
 
   B(int (*)[4]) : A(foo()) {}
   // expected-warning at -1 {{base_class_access::A' is uninitialized when used here to access 'base_class_access::A::foo'}}
+
+  virtual void f() = 0;
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zwuis wrote:

Would it be better to add new tests instead of modify existing tests?

https://github.com/llvm/llvm-project/pull/217715