libc 0.2.187 on Rust Cargo

This release contains a number of improvements related to 64-bit time_t configuration.
Of note the existing RUST_LIBC_UNSTABLE_* environment variables have been replaced
with configuration options. The new way to use these is:

RUSTFLAGS='--cfg=libc_unstable_musl_v1_2_3' cargo ...
RUSTFLAGS='--cfg=libc_unstable_gnu_time_bits="64"' cargo ...

Being able to set this via RUSTFLAGS makes it easier to only apply configuration to
specific targets (and notably, not the host if build scripts are used).

There are two other notable changes:

The 32-bit windows-gnu targets now respect libc_unstable_gnu_time_bits
uClibc now supports a similar configuration option:
```
RUSTFLAGS='--cfg=libc_unstable_uclibc_time64'
```

As a reminder, these options are under active development and may change in the future
(hence the "unstable" in the name). It likely that we will harmonize everything under a
single configuration option before considering them stable.

Support

Add support for aarch64-unknown-linux-pauthtest (#5065)
Add support for new QNX targets (#5241)
Better document breaking change policy and recommended usage (#5179)

Added

Android: Add POSIX_SPAWN_* constants (#5104)
Android: Add getpwent, setpwent, and endpwent (#5160)
Android: Add preadv2 and pwritev2 (#5157)
Android: Add seccomp_notif* structures (#5224)
Android: Add timer_[create, delete, getoverrun, gettime, settime] (#5108)
Apple: Add PROC_PIDT_SHORTBSDINFO and proc_bsdshortinfo (#5110)
Apple: Add SIOC* constants from sockio.h (#5263)
Apple: Add _IOR, _IOW, _IOWR (#5264)
Apple: Add bpf_program and bpf_insn (#5235)
Apple: Add additional kqueue constants (#5077)
Apple: Update vm_statistics64 with recently added fields (#5253)
Apple: add IN6_IFF_* and SIOCGIFAFLAG_IN6 (#5239)
Dragonfly: Add O_*, POSIX_FADV_*, NI*, and a few other missing constants (#5116)
Dragonfly: add fdatasync, dlvsym, reallocarray, qsort_r, pthread_*affinity_np, ftok, extattr_*, and dup3 (#5116)
Emscripten: Add in6_pktinfo (#5256)
FreeBSD: Add SOL_LOCAL (#5185)
FreeBSD: Add DLT_* constants (#5235)
FreeBSD: Add PROC_LOGSIGEXIT_* and PPROT_* (#4657)
FreeBSD: Add SO_RERROR (#5260)
FreeBSD: add IN6_IFF_*, in6_ifreq, and SIOCGIFAFLAG_IN6 (#5239)
FreeBSD: add _IO* helpers from sys/ioccom.h (#5239)
Glibc: Add PTHREAD_*_MUTEX_INITIALIZER_NP for riscv64 (#5094)
Glibc: Add new fields to struct tcp_info (#5215)
Linux: Add OPEN_TREE_NAMESPACE (#5145)
Linux: Add SECCOMP_IOCTL_* constants (#5224)
Linux: Add SO_DETACH_REUSEPORT_BPF (#5081)
Linux: Add futex_waitv (#5125)
Linux: Add constants for fsopen, fsconfig, fsmount, and fspick (#5145)
Linux: Add fields to statx present since 6.16 (#4621)
Linux: Add network entry API (#5049)
Linux: add ifaddrmsg and rtattr (#5234)
Linux: add sockaddr_iucv (#5041)
MacOS: Add ENOTCAPABLE (#4925)
Musl: Add renameat2 (#5113)
NuttX: Add F_SETFD (#5258)
NuttX: Add POLLRD* and POLLWR* constants (#5258)
NuttX: Add SO_KEEPALIVE and TCP keepalive constants (#5111)
NuttX: Add TCP_MAXSEG (#5258)
NuttX: Add eventfd and EFD_* constants (#5258)
NuttX: Add pipe2 (#5258)
NuttX: Add strerror_r (#5258)
NuttX: Add netinet structs and constants (#5258)
NuttX: Add socket structs, functions and constants (#5258)
QuRT: Add POSIX timer functions (#5091)
QuRT: Add missing pthread functions from QuRT SDK headers (#5091)
QuRT: Add missing unistd process and file functions (#5091)
QuRT: Add mqueue subsystem (message queues, select/pselect) (#5091)
Redox: Add *at and dirent functions (#5117)
Solarish: Add IP TTL and IPv6 Hop Limit consts (#5089)
Solarish: Add port_alert and PORT_ALERT* constants (#5203)
Solarish: add AI_CANONNAME (#5085)
aarch64: Add SYS_sendfile and SYS_fadvise64 constants (#5133)

Deprecated

Dragonfly: Deprecate compatibility aliases CPUCTL_RSMSR and UTX_DB_LASTLOG (#5116)

Fixed

breaking NetBSD: Correct ts from *const timespec to *mut timespec in _lwp_park` (#5169)
breaking Linux GNU: Change overflowing PTRACE_*ET_SYSCALL_USER_DISPATCH_CONFIG constants from u8 to c_uint (#4936)
Fix the soundness bug in the representation of extern types (#5021)
Cygwin: fix cpuset_t typo in CPU_ZERO (#5098)
Dragonfly: ABI fixes including regex offsets, ifaddrs, pthread barriers, process sizing fields, and mcontext alignment (#5116)
Dragonfly: Correct values of CPUCTL_CPUID*, EV_HUP, and EV_SYSFLAGS (#5116)
Emscripten: fix pthread type sizes for wasm64 (MEMORY64) (#5156)
Horizon: Fix the value of POLLOUT (#5090)
Linux: Correct the value of EPIOC[GS]PARAMS with nonstandard _IOC (#5188)
Make VxWorks shims unsafe (#3727)
NetBSD: Correct getmntinfo to link __getmntinfo13 (#5251)
QNX: Fix the value of PTHREAD_MUTEX_INITIALIZER (#5241)
QuRT: fix type and definition inaccuracies against SDK headers (#5091)
Windows: Correctly link to 32-bit time routines on 32-bit platforms (#5059)
uClibc: Fix constants accidentally removed (#5141)
uclibc: Fix build issues (#5046)
uclibc: Fix type of PRIO_PROCESS and friends (#5046)

Changed

AIX, TeeOS: Drop unneeded -> c_void (#5240)
Apple: Change AIO_LISTIO_MAX to account for changes in macOS 27 (#5253)
Glibc: Update the value of MS_NOUSER (#5215)
L4Re: Update definitions and test infra (#5275)
Linux: Update the value of SW_MAX and SW_CNT (#5215)
MacOS: Add swapped_count to vm_statistics64 (#4926)
Windows: Windows-GNU now respects libc_unstable_gnu_time_bits for 64-bit time_t config (#5062)

Removed

Dragonfly: Remove FreeBSD-only Elf32_Lword, ip_mreq_source, and IP_ constants (#5116)
Dragonfly: Remove private VM type bindings (#5116)
Linux: Remove KERN_REALROOTDEV and VM_LAPTOP_MODE (#5177)
VxWorks: Remove non-user-facing (kernel) API (#5129)

Other

Print config information if LIBC_BUILD_VERBOSE is set (#5272)
Annotate *LAST constants as potentially changing (#5120)
Annotate *MAX constants as potentially changing (#5122)
BSD: Annotate ELAST constants as potentially changing (#5118)
FreeBSD: Annotate RAND_MAX as potentially changing (#5119)
Linux, L4re: Annotate *NUM constants as potentially changing (#5123)
QNX: Restructure to support new platforms (#4984)
Unix: Annotate *COUNT constants as potentially changing (#5121)
uClibc: Add unstable support of 64-bit time_t (#5046)
(internal) FreeBSD: Replace unstable env to set version with an unstable cfg (#5201)
(internal) Glibc: Remove public configuration for file offset bits (#5268)
(internal) Linux: Delete config via RUST_LIBC_UNSTABLE_LINUX_TIME_BITS64 (#5197)
(internal) Replace RUST_LIBC_UNSTABLE env with libc_unstable* cfg (#4977)