message: Change function name, comments, and error message
diff: @@ -347,7 +347,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
  Some(metadata) => metadata,
  None => return Ok(-1),
  };
  - stat_write_buf(this, metadata, buf_op)
  + stat_macos_write_buf(this, metadata, buf_op)
  }
  fn stat_or_lstat(
  @@ -369,7 +369,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
  Some(metadata) => metadata,
  None => return Ok(-1),
  };
  - stat_write_buf(this, metadata, buf_op)
  + stat_macos_write_buf(this, metadata, buf_op)
  }
  fn statx(
  @@ -427,17 +427,23 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
  this.read_scalar(dirfd_op)?.to_machine_isize(&*this.tcx)?.try_into().map_err(|e| {
  err_unsup_format!("Failed to convert pointer sized operand to integer: {}", e)
  })?;
  - // we only support interpreting `path` as an absolute directory or as a directory relative
  - // to `dirfd` when the latter is `AT_FDCWD`. The behavior of `statx` with a relative path
  - // and a directory file descriptor other than `AT_FDCWD` is specified but it cannot be
  - // tested from `libstd`. If you found this error, please open an issue reporting it.
  + // We only support:
  + // * interpreting `path` as an absolute directory,
  + // * interpreting `path` as a path relative to `dirfd` when the latter is `AT_FDCWD`, or
  + // * interpreting `dirfd` as any file descriptor when `path` is empty and AT_EMPTY_PATH is
  + // set.
  + // The behavior of `statx` with a relative path and a directory file descriptor other than
  + // `AT_FDCWD` is specified but it cannot be tested from `libstd`. If you found this error,
  + // please open an issue reporting it.
  if !(
  path.is_absolute() ||
  dirfd == this.eval_libc_i32("AT_FDCWD")? ||
  (path.as_os_str().is_empty() && empty_path_flag)
  ) {
  throw_unsup_format!(
  - "Using statx with a relative path and a file descriptor different from `AT_FDCWD` is not supported"
  + "Using statx is only supported with absolute paths, relative paths with the file \
  + descriptor `AT_FDCWD`, and empty paths with the `AT_EMPTY_PATH` flag set and any \
  + file descriptor"
  )
  }
  @@ -631,7 +637,7 @@ impl FileMetadata {
  }
  }
  -fn stat_write_buf<'tcx, 'mir>(
  +fn stat_macos_write_buf<'tcx, 'mir>(
  ecx: &mut MiriEvalContext<'mir, 'tcx>,
  metadata: FileMetadata,
  buf_op: OpTy<'tcx, Tag>,
  