[Bug tree-optimization/102829] Redundant null check after atomic load from that address

[laurynas.biveinis at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102829

--- Comment #2 from Laurynas Biveinis <laurynas.biveinis at gmail dot com> ---
FWIW adding "if (this == nullptr) __builtin_unreachable();" between
__atomic_load_n and return fails to workaround this issue