- some tests are failing
- remove readlink, timegm and sig* functions in favor of the
  unix/mod.rs definitions
- remove time64_t (it is not defined for aarch64)
- move some definitions to android/b32.rs and create appropriated
  definitions in android/b64.rs

Add definitions to Android to allow fs2 crate compile

This is the only missing part to allow cargo to compile on android.

Make readdir available on all unix targets

The readdir_r call has problems, and we'll probably want to move to
readdir on many, if not most, unix targets. This patch makes readdir
available in unix, rather than just solaris as before.

See https://github.com/rust-lang/rust/issues/40021

Apparently a lot of libc's don't put "const" on the return type for
readdir, which causes type mismatch.

The readdir_r call has problems, and we'll probably want to move to
readdir on many, if not most, unix targets. This patch makes readdir
available in unix, rather than just solaris as before.

See https://github.com/rust-lang/rust/issues/40021

Add jail functions and constants for FreeBSD

These are the system calls for creating and managing jails on FreeBSD.

Add EPOLLEXCLUSIVE that is added in Linux 4.5.

Add [EPOLLEXCLUSIVE](https://kernelnewbies.org/Linux_4.5#head-64f3b13b9026133a232a418a27ac029e21fff2ba) that is added in Linux 4.5.

Added *_setpshared and *_getpshared bindings

Adding bindings to posix pthreads functions vital for IPC via shared memory.

That's my first PR into libc and I'm not proficient in unix systems programming, so I would really appreciate if someone reviewed it in case I missed something regardrless of the passed tests.
Thanks!

posix definitions should be used on Solaris

For compatibility reasons, Solaris historically had its header files
setup so that, unless specifically requested through specific header
defines, either the old pre-POSIX interfaces or POSIX.1c Draft 6
interfaces were used. However, in the case of rust, since these symbols
are linked directly instead of via system header files, the underlying
posix symbol name can be used directly instead.

These definitions should be corrected to match what they do on almost
every other platform.

Be aware this is a breaking change in terms of interface for any crates
/ consumers of these interfaces for Solaris.

Fixes #522

For compatibility reasons, Solaris historically had its header files
setup so that, unless specifically requested through specific header
defines, either the old pre-POSIX interfaces or POSIX.1c Draft 6
interfaces were used. However, in the case of rust, since these symbols
are linked directly instead of via system header files, the underlying
posix symbol name can be used directly instead.

These definitions should be corrected to match what they do on almost
every other platform.

Be aware this is a breaking change in terms of interface for any crates
/ consumers of these interfaces for Solaris.

Fixes #522

WIFCONTINUED function on Linux and FreeBSD

* Adds the missing WIFCONTINUED function to Linux (in `src/unix/notbsd/mod.rs`).
* Modifies the signature of WIFCONTINUED on FreeBSD (`src/unix/bsd/freebsdlike/mod.rs`) to be consistent with the ones on MacOS and Linux.

Add missing MSG_PEEK definition for Solaris

Fixes #517

Fixes #517

Auto merge of #516 - binarycrusader:master, r=alexcrichton

Correct solaris libc definitions:

* pthread_t is defined as uint_t, so must be c_uint, not uintptr_t, just
  as pthread_key_t is already defined
* fd_set is defined as long, so must be i32/i64 based on
  target_pointer_width; this also fixes an indirect endianness issue
  encountered on sparc
* FD_SETSIZE should be defined as 65536 when target_pointer_width = 64

Fixes #515

* pthread_t is defined as uint_t, so must be c_uint, not uintptr_t, just
  as pthread_key_t is already defined
* fd_set is defined as long, so must be i32/i64 based on
  target_pointer_width; this also fixes an indirect endianness issue
  encountered on sparc
* FD_SETSIZE should be defined as 65536 when target_pointer_width = 64

Fixes #515

Add AF_UNSPEC from Apple socket.h

[socket.h](https://opensource.apple.com/source/xnu/xnu-792.13.8/bsd/sys/socket.h) of Apple contains this definition so i'm not sure why it is missing from libc.
The same goes for other BSD-like OSes...
Is there some particular reasons why it is so?

Add types for `aarch64-unknown-freebsd`

Add wcstombs

Add `wcstombs` function to convert from wide chars to multibyte chars.

The `wcstombs(`) function conforms to ISO/IEC 9899:1999 (ISO C99)

Fix the i686-unknown-linux-musl target CI

`aarch64.rs` was copied and adapted from `x86_64.rs`.

The wcstombs() function conforms to ISO/IEC 9899:1999 (``ISO C99'')

Add IPPROTO_ICMP and IPPROTO_ICMPV6 system constants

This adds the protocol value for `ICMP` in both IPv4 and IPv6 variants.

ICMP protocol constant for IPv4 defined as `1` per [RFC 792](https://tools.ietf.org/html/rfc792)
ICMP protocol constant for IPv6 defined as `58` per [RFC 2463](https://tools.ietf.org/html/rfc2463#section-1)

#### Reference
[bsd/apple: netinet/in.h](https://opensource.apple.com/source/xnu/xnu-1699.24.8/bsd/netinet/in.h)
[bsd/freebsdlike/freebsd: netinet/in.h](https://github.com/freebsd/freebsd/blob/master/sys/netinet/in.h#L42)
[bsd/freebsdlike/dragonfly: netinet/in.h](https://github.com/DragonFlyBSD/DragonFlyBSD/blob/1f249c981c4e89e7cde1836a75b61cac36dc7ac5/sys/netinet/in.h#L64)
[bsd/netbsdlike: netinet/in.h](https://github.com/IIJ-NetBSD/netbsd-src/blob/af5d253140491f2d1816c59ecb8a4d8a8d927688/sys/netinet/in.h#L77)
[unix/haiku: netinet/in.h](https://github.com/haiku/haiku/blob/b65adbdfbc322bb7d86d74049389c688e9962f15/headers/posix/netinet/in.h#L54)
[unix/notbsd/linux: in.h](https://github.com/torvalds/linux/blob/8fa3b6f9392bf6d90cb7b908e07bd90166639f0a/include/uapi/linux/in.h#L31) - [unix/notbsd/linux: in6.h](https://github.com/torvalds/linux/blob/8fa3b6f9392bf6d90cb7b908e07bd90166639f0a/include/uapi/linux/in6.h#L134)

Adding missing WIFCONTINUED function on FreeBSD systems

This adds the WIFCONTINUED function to any FreeBSD-like system. Addresses #505

Add O_TMPFILE constant

add pipe2 to non-OSX BSD's

https://github.com/rust-lang/libc/issues/500