Auto merge of #2986 - dtolnay-contrib:ficlone, r=JohnTitor

Add FICLONE ioctl for linux aarch64

The ioctl number is the same on aarch64 as on x86_64:

- https://github.com/sunfishcode/linux-raw-sys/blob/v0.1.2/src/aarch64/ioctl.rs#L215-L216
- https://github.com/sunfishcode/linux-raw-sys/blob/v0.1.2/src/x86_64/ioctl.rs#L215-L216

Author: bors

libc-test/semver/linux-aarch64.txt

@@ -38,6 +38,8 @@ BPF_W
 BPF_X
 BPF_XOR
 CIBAUD
+FICLONE
+FICLONERANGE
 MADV_SOFT_OFFLINE
 MAP_SYNC
 SIGSTKFLT

src/unix/linux_like/linux/arch/generic/mod.rs

@@ -106,7 +106,9 @@ cfg_if! {
 }
 
 cfg_if! {
-    if #[cfg(any(target_arch = "x86", target_arch = "x86_64"))] {
+    if #[cfg(any(target_arch = "x86",
+                 target_arch = "x86_64",
+                 target_arch = "aarch64"))] {
         pub const FICLONE: ::c_ulong = 0x40049409;
         pub const FICLONERANGE: ::c_ulong = 0x4020940D;
     }