[llvm] [VPlan] Use DomTreeUpdater to automatically update DT for vector loop. (PR #92525)

[Renato Golin via llvm-commits]

https://github.com/rengolin commented:

I'm surprised by the simplicity of this patch. Not that it's wrong, just that it sounds simpler than the previous code that was meant to avoid complexity. :)

IIUC, instead of doing the full analysis at the end (in `updateDomintorTree`) you do it at the BB creation time (`BB::execute`) and wrapping time (`VP::execute`). That avoids the need for a whole update in the end, which is great.

In that sense, this looks really good to me, but I'm not an expert in DT updater, so I'll let others more comfortable in the area to approve.

https://github.com/llvm/llvm-project/pull/92525