[llvm] Fix compilation errors with -fforce-emit-vtables (PR #65456)

[David Blaikie via llvm-commits]

dwblaikie wrote:

(not sure about this direction/patch, but will take it up on the issue rather than in the review - since it's more about the general idea than the particular implementation details)

https://github.com/llvm/llvm-project/pull/65456