[Bug target/126350] -mno-sse doesn't disable SSE for _Atomic __int128

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126350

--- Comment #2 from H.J. Lu <hjl.tools at gmail dot com> ---
(In reply to Uroš Bizjak from comment #1)
> I don't see problem here. There is no requirement that libatomic uses SSE
> instructions. Also, -mno-sse is not x86_64 ABI compliant, so all used
> libraries should use -mno-sse too.
> 
> This is the same situation as compiling with -mno-sse and expecting that
> math library also doesn't use SSE instructions.
> 
> So, corresponding libatomic (without SSE insns) should be provided in this
> case.

libatomic is the part of gcc, which doesn't provide atomic functions
without SSE.