zfs: Cherry-pick upstream commit ef977fce6636 to fix macOS/arm64 bootstrap
Upstream commit message:
Support running FreeBSD buildworld on Arm-based macOS hosts Arm-based Macs are like FreeBSD and provide a full 64-bit stat from the start, so have no stat64 variants. Thus, define stat64 and fstat64 as aliases for the normal versions. Reviewed-by: Ryan Moeller <ryan@iXsystems.com> Signed-off-by: Jessica Clarke <jrtc27@jrtc27.com> Closes #11771
(cherry picked from commit 3a314eb5bb444ec019457e5aefaabb656fcb3d54)