[Bug middle-end/93940] crazy codegen bug on Og with builtin_constant_p, coverage, and pthread

[barry.revzin at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93940

--- Comment #2 from Barry Revzin <barry.revzin at gmail dot com> ---
Slightly more reduced: https://godbolt.org/z/5R9A5g