[PATCH] D38599: Remove warnings for dynamic_cast fallback.

[Jonathan Roelofs via Phabricator via cfe-commits]

jroelofs added a comment.

In https://reviews.llvm.org/D38599#893985, @danalbert wrote:

> In https://reviews.llvm.org/D38599#893903, @jroelofs wrote:
>
> > That reminds me... this does need a testcase or two.
>
>
> Oh, also, any test I add is going to fail, since the case I'm trying to account for here is not the default behavior.


That's what an `available_feature` + `// REQUIRES:` is for.


https://reviews.llvm.org/D38599