[llvm] [AVR] Support stack realignment (PR #187129)

[Patryk Wychowaniec via llvm-commits]

Patryk27 wrote:

> Did you build llvm with `-DLLVM_ENABLE_EXPENSIVE_CHECKS=On`?

Ok, with this flag active I can see two tests failing - thanks, investigating :mag:

https://github.com/llvm/llvm-project/pull/187129