Use linux-raw-sys for FIEMAP constants

[EliteTK]

Summary

This is a follow up to #20925, it makes use of the linux-raw-sys crate which is already in our dependency graph and has the constants which we were previously declaring inline. This doesn't really affect the amount of code, but it avoids needing to think about these values.

Test Plan

Existing coverage.

[woodruffw]

Nice!

[wegank]

I'm having the following error on loongarch64-linux:

error[E0432]: unresolved imports `linux_raw_sys::ioctl::FIEMAP_EXTENT_DATA_INLINE`, `linux_raw_sys::ioctl::FIEMAP_EXTENT_DELALLOC`, `linux_raw_sys::ioctl::FIEMAP_EXTENT_ENCODED`, `linux_raw_sys::ioctl::FIEMAP_EXTENT_LAST`, `linux_raw_sys::ioctl::FIEMAP_EXTENT_NOT_ALIGNED`, `linux_raw_sys::ioctl::FIEMAP_EXTENT_SHARED`, `linux_raw_sys::ioctl::FIEMAP_EXTENT_UNKNOWN`
  --> crates/uv-fs/src/space.rs:13:5
   |
13 |     FIEMAP_EXTENT_DATA_INLINE, FIEMAP_EXTENT_DELALLOC, FIEMAP_EXTENT_ENCODED, FIEMAP_EXTENT_LAST,
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^  ^^^^^^^^^^^^^^^^^^^^^^  ^^^^^^^^^^^^^^^^^^^^^  ^^^^^^^^^^^^^^^^^^ no `FIEMAP_EXTENT_LAST` in `ioctl`
   |     |                          |                       |
   |     |                          |                       no `FIEMAP_EXTENT_ENCODED` in `ioctl`
   |     |                          no `FIEMAP_EXTENT_DELALLOC` in `ioctl`
   |     no `FIEMAP_EXTENT_DATA_INLINE` in `ioctl`
14 |     FIEMAP_EXTENT_NOT_ALIGNED, FIEMAP_EXTENT_SHARED, FIEMAP_EXTENT_UNKNOWN, FS_IOC_FIEMAP,
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^  ^^^^^^^^^^^^^^^^^^^^  ^^^^^^^^^^^^^^^^^^^^^ no `FIEMAP_EXTENT_UNKNOWN` in `ioctl`
   |     |                          |
   |     |                          no `FIEMAP_EXTENT_SHARED` in `ioctl`
   |     no `FIEMAP_EXTENT_NOT_ALIGNED` in `ioctl`

It seems that constants like linux_raw_sys::ioctl::FIEMAP_EXTENT_DATA_INLINE aren't available on all architectures, so this PR breaks builds on platforms without them. Do you know how to fix this?

[woodruffw]

loong64 isn't one of the platforms we build or test for. Can you explain how you're doing the build?

[wegank]

I build with Nix on my machines, and the command should look something like nix build github:NixOS/nixpkgs#python3Packages.uv-build.

It seems that sunfishcode/linux-raw-sys#193 or sunfishcode/linux-raw-sys#195 should fix this on the linux_raw_sys side, but development there seems to be stalled; I wonder if there's anything we can do here...