[llvm] [AArch64] Refactor allocation of locals and stack realignment (PR #72028)

[Momchil Velikov via llvm-commits]

momchil-velikov wrote:

The patch is almost, but not quite NFC. The only difference should be that where we have adjacent allocation of stack space
for local SVE objects and non-local SVE objects the order of `sub sp, ...` and `addvl sp, ...` instructions is reversed because now it's done with a single call to `emitFrameOffset` and it handled the fixed part before the scalable part, e.g.
```
addvl sp, sp, #-2
sub sp, sp, #16, lsl #12
sub sp, sp, #16
```
becomes
```
sub sp, sp, #16, lsl #12
sub sp, sp, #16
addvl sp, sp, #-2
```


https://github.com/llvm/llvm-project/pull/72028