[Bug libstdc++/84568] libstdc++-v3 configure checks for atomic operations fail on riscv

[schwab--- via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84568

--- Comment #4 from Andreas Schwab <sch...@linux-m68k.org> ---
Not having inline atomics already breaks so many things.