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"libc: changes to ppc64le musl branch to support building of rust on Alpine"

has removed stuff from mod.rs and added it to some submodules, but
missed the aarch64 submodule.

This copies the stuff that that commit added to the x86_64.rs submodule
and puts it into aarch64.rs.

illumos header translation is wrong 02000000 should be 0x80000

I am recently getting into rust and discovered that tokio wasn't working on illumos.  I traced it back to mio but ultimately the issue ended up being this value in the libc crate.  It looks like the octal value isn't properly translated to the rust crate as hex.  Here's a test program I was using on linux and illumos:

```rust
extern crate libc;

#[allow(dead_code)]
const ILLUMOS_EPOLL_CLOEXEC: i32 = 0x80000;

fn find_func() -> usize {
    unsafe { libc::dlsym(libc::RTLD_DEFAULT, "epoll_create1\0".as_ptr() as *const _) as usize }
}

fn main() {
    let addr = find_func();

    #[allow(unused_variables)]
    let hex = format!("{:x}", addr);

    // I think the position changes per run on linux due to something like ASLR
    // so we only test on solaris for this use case
    #[cfg(target_os = "solaris")]
    assert_eq!(hex, "ffffbf7fff226fe0"); // confirmed with addrtosymstr

    unsafe {
        let f = std::mem::transmute::<usize, fn(i32) -> i32>(addr);

        #[cfg(target_os = "linux")]
        let epfd = f(libc::EPOLL_CLOEXEC);

        #[cfg(target_os = "solaris")]
        let epfd = f(ILLUMOS_EPOLL_CLOEXEC);

        println!("call to epoll_create1 returned: {}", epfd);
    }
}
```

Which outputs the following:

```
# cargo run
    Finished dev [unoptimized + debuginfo] target(s) in 0.04s
     Running `target/debug/dlsym`
call to epoll_create1 returned: 3
```

Edit: typo

Simplify the stdbuild section

Found this when encountering the code in the rustc submodule and changing the allow for the warnings to deny.

* `no_std` is stable so it does not have to be listed in the `feature` attribute
* `no_std` as an attribute for the crate is already implied by the `#![cfg_attr(not(feature = "use_std"), no_std)]` below
* `staged_api` as an attribute gives a warning. That also matches my knowledge.

Haiku: Add more IP_* and IPV6_* constants.

These are used in the socket2 library.

Add _SC_PHYS_PAGES on macOS

libc: changes to ppc64le musl branch to support building of rust on A…

…lpine

This PR includes changes to the libc musl branch to include the correct defines & declarations to support powerpc64.  Values that needed changes to a definition for powerpc64.rs that existed higher in the branch also resulted in a change that moved the definition down to the b32/mod.rs, b64/x86_64.rs to ensure that builds continued to work on those architectures.

Verification was done building rust for both ppc64le and x86_64 on Alpine as described in the git project
https://github.com/mksully22/ppc64le_alpine_rust_1.26.2

Add getpid on Redox

None

add fdopendir on macOS

Fixes #1017

I moved it up to src/unix/mod.rs, as it's specified in POSIX.1-2008 and
appears to be implemented on every Unix-like system.

The symbol names on macOS appear similar to those for opendir; I found
them via the commands below. I tested the x86_64 version;
fdopendir$INODE64 worked as expected.

$ nm -arch x86_64 /usr/lib/system/libsystem_c.dylib | grep fdopendir
000000000007ea6d T _fdopendir
000000000002ba97 T _fdopendir$INODE64
$ nm -arch i386 /usr/lib/system/libsystem_c.dylib | grep fdopendir
00082d1e T _fdopendir
0002b528 T _fdopendir$INODE64$UNIX2003
00082d1e T _fdopendir$UNIX2003

added renamex_np, renameatx_np

these function can be used to atomically swap files

- added 2 macos specific functions - `renamex_np` and `renameatx_np` and two constants `RENAME_SWAP` and `RENAME_EXCL`
  - [macos stdio.h](https://github.com/apple/darwin-xnu/blob/0ddccd8/bsd/sys/stdio.h#L45-L48)
  - [docs](http://www.manpagez.com/man/2/renameatx_np/osx-10.12.3.php)
- ~added linux specific `renameat2`. according to the [docs](http://man7.org/linux/man-pages/man2/rename.2.html#VERSIONS) it was added to Linux in kernel 3.15.~

add net/if_arp.h definitions

This is based on the contents of include/net/if_arp.h on my Linux system.

These are used in the socket2 library.

amend to add style changes
amend to add style changes

Fixes #1017

I moved it up to src/unix/mod.rs, as it's specified in POSIX.1-2008 and
appears to be implemented on every Unix-like system.

The symbol names on macOS appear similar to those for opendir; I found
them via the commands below. I tested the x86_64 version;
fdopendir$INODE64 worked as expected.

$ nm -arch x86_64 /usr/lib/system/libsystem_c.dylib | grep fdopendir
000000000007ea6d T _fdopendir
000000000002ba97 T _fdopendir$INODE64
$ nm -arch i386 /usr/lib/system/libsystem_c.dylib | grep fdopendir
00082d1e T _fdopendir
0002b528 T _fdopendir$INODE64$UNIX2003
00082d1e T _fdopendir$UNIX2003

Add some termios constants for sparc64

Bump version to 0.2.42

Closes https://github.com/rust-lang/libc/issues/1011

make dox::mem::size_of a const fn

add more built-in traits to dox.rs

Add/fix bitwise operation traits in dox.rs

Fix sparc64 builds

Partially fixes #987.

add rtentry

Add `gethostname` support to Redox module

We need this for hostname support in Ion shell.