[llvm] [llvm] Ensure propagated constants in the vtable are aligned (PR #136630)

[Paul Kirth via llvm-commits]

ilovepi wrote:

> > I see some new tests. Can we get those precommited, so it's easy to understand the full delta of your compiler change?
> 
> You're referring to having a PR with just `virtual-const-prop-small-alignment-32/64.ll` without the functional changes in this PR?

yes, if possible.  That way, when you update the test in this PR, it will be easy to understand what's changing in the new cases.

https://github.com/llvm/llvm-project/pull/136630