[llvm] [RISCV] Emit .note.gnu.property section when Zicfiss-based shadow stack is enabled (PR #127036)

[Fangrui Song via llvm-commits]

MaskRay wrote:

Is GNU_PROPERTY_RISCV_FEATURE_1_AND documented anywhere? When other targets introduced GNU_PROPERTY to compilers, there had been psABI documentation.

https://github.com/llvm/llvm-project/pull/127036