feat: add ioctl flags in linux/if_tun.h

fix: values under different architectures

style: update code style

fix: remove `TUNSETCARRIER` and `TUNGETDEVNETNS`

feat: add `TUNSETCARRIER` and `TUNGETDEVNETNS` in `gnu`

style: update code style

(backport <rust-lang#3960>)
(cherry picked from commit c24c516)

Author: wlynxg

src/unix/linux_like/linux/gnu/mod.rs

@@ -1206,6 +1206,29 @@ cfg_if! {
     }
 }
 
+cfg_if! {
+    if #[cfg(any(target_arch = "x86",
+                 target_arch = "x86_64",
+                 target_arch = "arm",
+                 target_arch = "aarch64",
+                 target_arch = "loongarch64",
+                 target_arch = "riscv64",
+                 target_arch = "s390x"))] {
+        pub const TUNSETCARRIER: ::Ioctl = 0x400454e2;
+        pub const TUNGETDEVNETNS: ::Ioctl = 0x54e3;
+    } else if #[cfg(any(target_arch = "mips",
+                        target_arch = "mips64",
+                        target_arch = "powerpc",
+                        target_arch = "powerpc64",
+                        target_arch = "sparc",
+                        target_arch = "sparc64"))] {
+        pub const TUNSETCARRIER: ::Ioctl = 0x800454e2;
+        pub const TUNGETDEVNETNS: ::Ioctl = 0x200054e3;
+    } else {
+        // Unknown target_arch
+    }
+}
+
 extern "C" {
     pub fn fgetspent_r(
         fp: *mut crate::FILE,