Linux defines a waitid type `P_PIDFD`, for use with process file
descriptors (`pidfd`). Add that constant.

In libc-test, add linux/wait.h to the Linux-specific and
Android-specific headers, to get the definition. Exclude it on Android
and musl for now, though, as the versions in CI don't have it yet.

add openpty and forkpty implementation for illumos systems

At time of writing, illumos systems do not provide an implementation of
the openpty() and forkpty() wrappers provided on some other UNIX
systems.  While we expect to grow an implementation, it seems prudent to
provide a compatibility routine here first to unblock illumos support in
the popular nix crate.

DevkitPPC does not support unix sockets natively, meaning that bindings
to these functions was removed for powerpc targets with "nintendo" as
vendor.

Suggested target json files:

Nintendo Gamecube:
```
{
  "arch": "powerpc",
  "data-layout": "E-m:e-p:32:32-i64:64-n32",
  "dynamic-linking": false,
  "env": "newlib",
  "executables": true,
  "has-elf-tls": false,
  "has-rpath": true,
  "linker-flavor": "gcc",
  "llvm-target": "powerpc-eabi",
  "max-atomic-width": 32,
  "os": "dolphin",
  "target-c-int-width": "32",
  "target-endian": "big",
  "target-family": "unix",
  "target-mcount": "_mcount",
  "target-pointer-width": "32",
  "vendor": "nintendo"
}
```

Nintendo Wii:
```
{
  "arch": "powerpc",
  "data-layout": "E-m:e-p:32:32-i64:64-n32",
  "dynamic-linking": false,
  "env": "newlib",
  "executables": true,
  "has-elf-tls": false,
  "has-rpath": true,
  "linker-flavor": "gcc",
  "llvm-target": "powerpc-eabi",
  "max-atomic-width": 32,
  "os": "revolution",
  "target-c-int-width": "32",
  "target-endian": "big",
  "target-family": "unix",
  "target-mcount": "_mcount",
  "target-pointer-width": "32",
  "vendor": "nintendo"
}
```

Add more constants for getnameinfo on android

add ucred(3C) support for illumos and Solaris systems

This series of routines allows the caller to determine the credentials
of another process by pid, or of the process on the remote end of a UNIX
domain socket.  The ucred_t is an opaque object with accessor routines,
and must be freed through ucred_free(3C) after use.

Add sys/personality.h constants for Linux

Bump version to 0.2.74

Deprecate CTL_P1003_1B_MAXID

This change addresses two style errors found in PR review:
* indent and linebreak in CMSG_NXTHDR
* prefer `0 as *mut cmsghdr` over `core::ptr::nul_mut()`

This includes changes which will allow us to successfully build `libstd` for the PSP.

Create macros for defining Copy/Clone on enums and struct(), use for psp

It's been removed in FreeBSD 13 (svn r363622), and never had any
legitimate use outside of the base system anyway.

Fix styling

Re-run CI

This change defines and implements functions for the Fuchsia platform
corresponding to the C library CMSG_* macros, used for processing socket
control messages sent or received using the recv_msg(2)/send_msg(2)
syscalls.

Update FreeBSD 11 to 11.4-RELEASE

Add "_aligned_malloc" on windows platform

Use `build-std` feature instead of using `cargo-xbuild`

Add `PTRACE_EVENT_STOP`

Expose IP_FREEBIND constant for linux

Co-authored-by: Yuki Okushi <huyuumi.dev@gmail.com>

Declare `utmpx` on musl

https://man7.org/linux/man-pages/man3/clock_getcpuclockid.3.html

VMADDR_CID_RESERVED is NOT available from Linux v5.6.
VMADDR_CID_LOCAL is available only on Linux >= v5.6.

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>