Apparently the 17.10 image broke?

fuchsia: mxio was renamed to fdio

As a side effect of the rename of the Magenta kernel to Zircon, the mxio library was renamed to fdio, and the linker directive needs to be updated.

Define additional IPPROTO_* constants.

Define additional IPPROTO_* constants, e.g. for DCCP and SCTP. These constants are standard across all system types -- the values are those assigned to the protocol by the IANA:
https://www.iana.org/assignments/protocol-numbers/protocol-numbers.xhtml

Bring back cfg_target_vendor, which is still used

r? @alexcrichton https://github.com/rust-lang/rust/pull/44515#issuecomment-330036756

Update s3 download locations

Add additional interface flags (IFF_)

Adds the three missing IFF_ constants (IFF_LOWER_UP, IFF_DORMANT, and IFF_ECHO) per nix-rust/nix#764

Make stdbuild a cargo feature

Also invert the default feature / no std arrangement. The default
still uses std, but no_std now requires opt-in instead of opt-out.

This is work toward removing the shim in rustc.

Also remove unneeded platform gating

Add timerfd API on Linux

This change adds the Linux-specific timerfd API to libc.

```C
#include <sys/timerfd.h>

int timerfd_create(int clockid, int flags);
int timerfd_gettime(int fd, struct itimerspec *curr_value);
int timerfd_settime(int fd, int flags,
                    const struct itimerspec *new_value,
                    struct itimerspec *old_value);
```

The timerfd API has been available since kernel 2.6.25 and in glibc since version 2.8.

I'm not sure if I put the changes in the right places, so please review with great care.

Linux/Android: re-add initgroups

This was removed in #742

This change adds the Linux-specific timerfd API to libc.

Add networking symbols for uclibc/x86_64

Add Solaris 10 support

Haiku updates

Remove caching and fix FreeBSD tests

Unlike Illumos and Solaris 11, Solaris 10 does not support posix_memalign, so this change is needed for Solaris 10 support.

apple: Add VM_* constants from mach/vm_statistics.h

Closes #736.

Fix compile on sparc64