[clang] [clang][bytecode] Disable preservenone attribute on clang19+asan (PR #189377)

[Chandler Carruth via cfe-commits]

chandlerc wrote:

Clang 21 ASan also crashes with:
```
error: Stack realignment in presence of dynamic allocas is not supported with this calling convention.
```

Specifically:
```
> /home/linuxbrew/.linuxbrew/Cellar/llvm at 21/21.1.8/bin/clang++ --version
Homebrew clang version 21.1.8
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /home/linuxbrew/.linuxbrew/Cellar/llvm at 21/21.1.8/bin
```

I'm testing Clang 22 now, and based on what that says I'll send a PR to adjust this to either start at 21 and older or to exempt _all_ ASan builds.

But I'd also like to flag that this has been a pretty disruptive patch for users of LLVM. =/ I think in the future would be better to revert and test more broadly rather than trying to fix forward over several days.

https://github.com/llvm/llvm-project/pull/189377