[llvm] [SystemZ] Eliminate call sequence instructions early. (PR #77812)

[Jonas Paulsson via llvm-commits]

JonPsson1 wrote:

Do we need to support the inline-asm alignstack attribute? In that case we need to do a similar handling of INLINEASM[_BR] instructions to set the adjustsStack flag. My understanding is however that the stack is always aligned at 8 bytes and therefore this is not needed...?

https://github.com/llvm/llvm-project/pull/77812