Expose futimens and utimensat on FreeBSD and DragonFly

Should have sent this out with #1084 but I didn't notice then that these were missing (see https://github.com/nix-rust/nix/pull/944).

Haven't been able to test these locally as I do not have access to these platforms. Will rely on CI to verify these for me.

Expose futimens and utimensat on Apple platforms

Entries copy/pasted from `netbsdlike/mod.rs`.

Add fallocate64 and posix_fallocate64 bindings

These are necessary for large file support on 32-bit platforms,
following the same pattern as 74825222 ("Add bindings for
-D_FILE_OFFSET_BITS=64").

Signed-off-by: Daniel Verkamp <dverkamp@chromium.org>

These are necessary for large file support on 32-bit platforms,
following the same pattern as 74825222 ("Add bindings for
-D_FILE_OFFSET_BITS=64").

Signed-off-by: Daniel Verkamp <dverkamp@chromium.org>

Re-export core::ffi::c_void if it exists

This is the second part of the implementation of [RFC 2521](https://github.com/rust-lang/rfcs/pull/2521), replacing the definition of `c_void` in libc with a re-export of the type from `core::ffi::c_void` on builds it exists for.

This uses the re-export for rustc version `1.31.0` or greater, as `1.30.x` was the current nightly when [the PR for the changes to libcore and libstd](https://github.com/rust-lang/rust/pull/53910) was merged, so I'm assuming the first nightly they will appear in will be `1.31.0`; is this acceptable?

cc rust-lang/rust#53856

Theoretically test statics

There are none of them in `libc` except for `__progname` on Android, but
that one cannot be tested because it's not present in any header files.

Add new FreeBSD socket option SO_REUSEPORT_LB.

FreeBSD 12, which is scheduled to be released soon, has a new socket option SO_REUSEPORT_LB.
From setsockopt man page:
     SO_REUSEPORT_LB allows completely duplicate bindings by multiple
     processes if they all set SO_REUSEPORT_LB before binding the port.
     Incoming TCP and UDP connections are distributed among the sharing
     processes based on a hash function of local port number, foreign IP
     address and port number. A maximum of 256 processes can share one socket.

Fix mips-unknown-linux-uclibc target

The mips(el)-unknown-linux-uclibc target has apparently been broken in one way or another for over a year. This PR is the patch it took to successfully build a beta toolchain that could support it.

I am pretty sure these fixes are the right answer, after considerable digging in both the libc crate source (_pub-use pub-use everywhere, and not a hint to link_) and the uClibc source (_it's not POSIX, but they've shipped it since 2007, so close enough_).

For those who don't know, the *-uClibc targets are the only way (AFAIK) to create Rust binaries which run on Linux kernels prior to 2.6. It is a use case that is getting quite rare these days, but is still present in embedded ecosystems where chip vendors never migrated their hardware support to newer kernel versions.

Here's hoping these Rust toolchain targets find a maintainer someday.

cc rust-lang/rust#43503

Add a couple more ELF types

There are none of them in `libc` except for `__progname` on Android, but
that one cannot be tested because it's not present in any header files.

Add some more elf types

Add mallopt

First time contributor. Thanks for the excellent contributing guide.
I'm not quite sure I put the method in the right place. [The GNULib docs](https://www.gnu.org/software/gnulib/manual/html_node/mallopt.html) say its not on Android 7.1, but there are [mentions of it in some android headers](https://android.googlesource.com/platform/bionic/+/master/libc/include/malloc.h).

Add additional Redox OS functions

This adds `chown`, `fchown`, `setenv`, and `unsetenv` to the `redox` module, and reorders the functions by name

Undo division of in6_addr on Fuchsia

sparc64 tests are passing again

Closes #1064 .

Closes #1064 .

Fix and cleanup Fuchsia

Remove false support for power and mips.
Fix aarch64 definitions of nlink_t and blksize_t.

r? @alexcrichton

cc @sulanov

Remove false support for power and mips.
Fix aarch64 definitions of nlink_t and blksize_t.

Add TIOCGWINSZ accessor to solaris module

Signed-off-by: Ian Henry <ihenry@chef.io>

I recently noticed downstream that these request values were unavailable and needed for things like [the pb crate](https://github.com/a8m/pb). To get access to the request value I ran the following simple C code:
```
#include <sys/ioctl.h>
#include <stdio.h>
#include <sys/termios.h>

int main(int argc, char **argv) {
    printf("Code: 0x%04lx\n", TIOCGWINSZ);
    printf("Code: 0x%04lx\n", TIOCSWINSZ);
    return 0;
}
```
To then validate the change I ran the following simple rust:
```
extern crate libc;

use libc::{ioctl, winsize, STDOUT_FILENO, TIOCGWINSZ};

fn main() {
    let mut wsize = winsize {
        ws_row: 0,
        ws_col: 0,
        ws_xpixel: 0,
        ws_ypixel: 0,
    };
    unsafe {
        ioctl(STDOUT_FILENO, TIOCGWINSZ, &mut wsize);
    }
    println!("Sizes: {{ rows: {}, cols: {}, xpixel: {}, ypixel: {} }}",
             wsize.ws_row,
             wsize.ws_col,
             wsize.ws_xpixel,
             wsize.ws_ypixel);
}
```

Signed-off-by: Ian Henry <ihenry@chef.io>