[llvm-branch-commits] [libcxx] release/20.x: [libc++] Avoid including <features.h> on arbitrary platforms (#125587) (PR #127310)

[Nico Weber via llvm-branch-commits]

nico wrote:

(FYI, possibly causes test failures on mac: https://github.com/llvm/llvm-project/pull/125587#issuecomment-2661004287)

https://github.com/llvm/llvm-project/pull/127310