[clang] [CIR] Upstream vtable thunk handling (PR #183629)

[Amr Hesham via cfe-commits]

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@@ -13,10 +13,12 @@
 #include "CIRGenVTables.h"
 
 #include "CIRGenCXXABI.h"
+#include "CIRGenFunction.h" // Is this needed?
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AmrDeveloper wrote:

Leftover? 

https://github.com/llvm/llvm-project/pull/183629