[libc-commits] [libc] [libc] lift app's definition out of startup (PR #75717)

[Schrodinger ZHU Yifan via libc-commits]

SchrodingerZhu wrote:

@michaelrj-google Default values are needed in overlay mode, where the `libc` is not loaded by its loader such that `AppProperties` is not available. For example, I may need to check if `auxv_ptr` is `nullptr` for `getauxval` and fallback to syscall/fs based approaches.

https://github.com/llvm/llvm-project/pull/75717