[llvm] [CodeGen] Get stack alignment from TargetFrameLowering (NFCI) (PR #105477)

[Sergei Barannikov via llvm-commits]

s-barannikov wrote:

> > DL.getStackAlignment() because the DataLayout method asserts if the stack alignment wasn't specified.
> 
> This is just a bug that should be fixed? In every other context the datalayout treats fields as having default values

There is no default value for this one. Quoting LangRef:

> If omitted, the natural stack alignment defaults to “unspecified”, which does not prevent any alignment promotions.

I'm going to change the result type of `DL.getStackAlign()` to `MaybeAlign` in the next PR, but I though it may make sense to switch CodeGen to use TFL method in any case.


https://github.com/llvm/llvm-project/pull/105477