[libcxx-commits] [libcxx] [libc++] use copy_file_range for fs::copy (PR #109211)

[Martin Storsjö via libcxx-commits]

mstorsjo wrote:

> I don't have the opportunity to test this on FreeBSD, but I think the FreeBSD folks will want a look at this. Sadly I don't know any by name, perhaps someone could CC the relevant person(s).

CC @emaste 

@Jannik2099 Note that the CI environment does contain a FreeBSD setup, which shows a failure (a somewhat boring one):
```
/home/buildkite/.buildkite-agent/builds/freebsd-test-1/llvm-project/libcxx-ci/libcxx/src/filesystem/operations.cpp:183:6: error: unused function 'copy_file_impl_copy_file_range' [-Werror,-Wunused-function]
  183 | bool copy_file_impl_copy_file_range(FileDescriptor& read_fd, FileDescriptor& write_fd, error_code& ec) {
      |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
```
(There are also a couple other similar failing cases in the same CI run on buildkite.)

https://github.com/llvm/llvm-project/pull/109211