[clang] [Clang] Enable -fpointer-tbaa by default. (PR #117244)

[Florian Hahn via cfe-commits]

fhahn wrote:

> This seems reasonable to me. Since it's standards-compliant, has a specific opt-out flag, and is overridden by the general `-fno-strict-aliasing` flag, I don't see any need for the RFC process. Still, you should definitely wait for more feedback, especially from @AaronBallman.
> 
> This is not a prerequisite for landing the patch — or a requirement at all, for that matter — but I think it'd be great if you could make a sort of capstone post on the forums talking about this work and your performance analysis in more detail.

Thanks @rjmccall, I'll try to write something up, although it might take a few weeks.

https://github.com/llvm/llvm-project/pull/117244