[llvm] [clang] [AArch64] Support optional constant offset for constraint "S" (PR #80255)

[Fangrui Song via cfe-commits]

MaskRay wrote:

I have some notes about these constraints https://maskray.me/blog/2024-01-30-raw-symbol-names-in-inline-assembly

https://github.com/llvm/llvm-project/pull/80255