linux: Added _IO, _IOW, _IOR, _IOWR to the exported API

(backport <rust-lang#4325>)
(cherry picked from commit cf6113d)

Author: Mr2Brainless

libc-test/semver/linux.txt

@@ -3553,9 +3553,13 @@ _CS_POSIX_V7_LPBIG_OFFBIG_LDFLAGS
 _CS_POSIX_V7_LPBIG_OFFBIG_LIBS
 _CS_POSIX_V7_LPBIG_OFFBIG_LINTFLAGS
 _CS_POSIX_V7_WIDTH_RESTRICTED_ENVS
+_IO
 _IOFBF
 _IOLBF
 _IONBF
+_IOR
+_IOW
+_IOWR
 _PC_2_SYMLINKS
 _PC_ALLOC_SIZE_MIN
 _PC_ASYNC_IO

src/unix/linux_like/linux/mod.rs

@@ -5939,22 +5939,22 @@ const fn _IOC(dir: u32, ty: u32, nr: u32, size: usize) -> u32 {
 }
 
 /// Build an ioctl number for an argumentless ioctl.
-pub(crate) const fn _IO(ty: u32, nr: u32) -> u32 {
+pub const fn _IO(ty: u32, nr: u32) -> u32 {
     _IOC(_IOC_NONE, ty, nr, 0)
 }
 
 /// Build an ioctl number for an read-only ioctl.
-pub(crate) const fn _IOR<T>(ty: u32, nr: u32) -> u32 {
+pub const fn _IOR<T>(ty: u32, nr: u32) -> u32 {
     _IOC(_IOC_READ, ty, nr, size_of::<T>())
 }
 
 /// Build an ioctl number for an write-only ioctl.
-pub(crate) const fn _IOW<T>(ty: u32, nr: u32) -> u32 {
+pub const fn _IOW<T>(ty: u32, nr: u32) -> u32 {
     _IOC(_IOC_WRITE, ty, nr, size_of::<T>())
 }
 
 /// Build an ioctl number for a read-write ioctl.
-pub(crate) const fn _IOWR<T>(ty: u32, nr: u32) -> u32 {
+pub const fn _IOWR<T>(ty: u32, nr: u32) -> u32 {
     _IOC(_IOC_READ | _IOC_WRITE, ty, nr, size_of::<T>())
 }