[libcxx-commits] [libcxx] [libc++] Build the library with C++26 (PR #181021)

[Louis Dionne via libcxx-commits]

ldionne wrote:

Regardless of the outcome of updating the CMake version, I am trying to use `-std=c++26` directly in this patch to remove the dependency on that RFC.

https://github.com/llvm/llvm-project/pull/181021