[libc-commits] [libc] [libc][math][c23] Add acospif16() function (PR #134664)

[via libc-commits]

lntue wrote:

So this is the errors from the buildkite bot:
```
FAILED: projects/libc/src/math/generic/CMakeFiles/libc.src.math.generic.acospif16.__NO_FMA_OPT.dir/acospif16.cpp.o 
...
/var/lib/buildkite-agent/builds/linux-56-59b8f5d88-bt7k7-1/llvm-project/github-pull-requests/libc/src/math/generic/acospif16.cpp:70:17: error: no member named 'polyeval' in namespace '__llvm_libc_21_0_0_git::fputil'
       fputil::polyeval(xsq, POLY_COEFFS[0], POLY_COEFFS[1], POLY_COEFFS[2],
```

https://github.com/llvm/llvm-project/pull/134664