[libcxx-commits] [libcxx] [libc++] Always define _LIBCPP_GLIBC_PREREQ (PR #169405)

[Anthony Latsis via libcxx-commits]

AnthonyLatsis wrote:

@philnik777 ping. This breaks the libcxx build for wasm32-wasip1:

```
/home/build-user/llvm-project/libcxx/src/filesystem/operations.cpp:255:18: error: no member named 'copy_file_range' in the global namespace
  255 |     if ((res = ::copy_file_range(read_fd.fd, &off_in, write_fd.fd, &off_out, count, 0)) == -1) {
      |                  ^~~~~~~~~~~~~~~
```

https://github.com/llvm/llvm-project/pull/169405