[llvm] [AArch64] Roundup newly allocated stack size according -mstack-alignment (PR #100859)

[David Green via llvm-commits]

https://github.com/davemgreen commented:

Does this option mean that the stack must be N into and out of any function being compiled? That sounds like it creates a new ABI that would not necessarily be followed by any external routines.

https://github.com/llvm/llvm-project/pull/100859