fix wrong return value from wmemmove on forward copies
replace stub with working strcasestr
namespace conformance to latest standards in strings.h
implement non-stub strverscmp

patch by Isaac Dunham.
fix integer type issue in strverscmp

lenl-lenr is not a valid expression for a signed int return value from
strverscmp, since after implicit conversion from size_t to int this
difference could have the wrong sign or might even be zero. using the
difference for char values works since they're bounded well within the
range of differences representable by int, but it does not work for
size_t values.
fix cruft in utmp.h that was broken by changes in utmpx.h

patch by Chris Spiegel.
fix wrong float_t on x86_64

x86_64 does not have excess precision, at all
fix some obscure header type size/alignment issues
fix types for wctype_t and wctrans_t

wctype_t was incorrectly "int" rather than "long" on x86_64. not only
is this an ABI incompatibility; it's also a major design flaw if we
ever wanted wctype_t to be implemented as a pointer, which would be
necessary if locales support custom character classes, since int is
too small to store a converted pointer. this commit fixes wctype_t to
be unsigned long on all archs, matching the LSB ABI; this change does
not matter for C code, but for C++ it affects mangling.

the same issue applied to wctrans_t. glibc/LSB defines this type as
const __int32_t *, but since no such definition is visible, I've just
expanded the definition, int, everywhere.

it would be nice if these types (which don't vary by arch) could be in
wctype.h, but the OB XSI requirement in POSIX that wchar.h expose some
types and functions from wctype.h precludes doing so. glibc works
around this with some hideous hacks, but trying to duplicate that
would go against the intent of musl's headers.
fix missing type error in grp.h from adding fgetgrent
fix epoll structure alignment on non-x86_64 archs

this fix is far from ideal and breaks the rule of not using
arch-specific #ifdefs, but for now we just need a solution to the
existing breakage.

the underlying problem is that the kernel folks made a very stupid
decision to make misalignment of this struct part of the kernel
API/ABI for x86_64, in order to avoid writing a few extra lines of
code to handle both 32- and 64-bit userspace on 64-bit kernels. I had
just added the packed attribute unconditionally thinking it was
harmless on 32-bit archs, but non-x86 32-bit archs have 8-byte
alignment on 64-bit types.
remove soname from libc.so/ld-musl

it serves no purpose (binaries linked against musl as -lc/libc.so
automatically get the right DT_NEEDED value of libc.so) and causes
ldconfig to misbehave (making a symlink to ld-musl named libc.so in
/lib). ldconfig is not used on pure musl systems, but if ld-musl is
installed on a system where it's not the primary libc, this will
pollute the system /lib with a symlink to musl named libc.so, which
should NOT exist and could cause problems linking native apps. also,
the existence of the soname caused spurious warnings from ldconfig
when /lib and /usr/lib were the same physical directory.
fix multiple bugs in syslog interfaces

1. as reported by William Haddon, the value returned by snprintf was
wrongly used as a length passed to sendto, despite it possibly
exceeding the buffer length. this could lead to invalid reads and
leaking additional data to syslog.

2. openlog was storing a pointer to the ident string passed by the
caller, rather than copying it. this bug is shared with (and even
documented in) other implementations like glibc, but such behavior
does not seem to meet the requirements of the standard.

3. extremely long ident provided to openlog, or corrupt ident due to
the above issue, could possibly have resulted in buffer overflows.
despite having the potential for smashing the stack, i believe the
impact is low since ident points to a short string literal in typical
application usage (and per the above bug, other usages will break
horribly on other implementations).

4. when used with LOG_NDELAY, openlog was not connecting the
newly-opened socket; sendto was being used instead. this defeated the
main purpose of LOG_NDELAY: preparing for chroot.

5. the default facility was not being used at all, so all messages
without an explicit facility passed to syslog were getting logged at
the kernel facility.

6. setlogmask was not thread-safe; no synchronization was performed
updating the mask. the fix uses atomics rather than locking to avoid
introducing a lock in the fast path for messages whose priority is not
in the mask.

7. in some code paths, the syslog lock was being unlocked twice; this
could result in releasing a lock that was actually held by a different
thread.

some additional enhancements to syslog such as a default identifier
based on argv[0] or similar may still be desired; at this time, only
the above-listed bugs have been fixed.
add deprecated SIGIOT alias for SIGABRT

reportedly some programs (e.g. showkeys in the kbd package) use it.
remove cruft from pre-posix_spawn version of the system function
rewrite popen to use posix_spawn instead of fragile vfork hacks
in pipe2, use pipe() rather than __syscall(SYS_pipe, ...) for fallback

SYS_pipe is not usable directly in general, since mips has a very
broken calling convention for the pipe syscall. instead, just call the
function, so that the mips-specific ugliness is isolated in
mips/pipe.s and not copied elsewhere.
provide emulation of fcntl F_DUPFD_CLOEXEC on old kernels

I'm not entirely happy with the amount of ugliness here, but since
F_DUPFD_CLOEXEC is used elsewhere in code that's expected to work on
old kernels (popen), it seems necessary. reportedly even some modern
kernels went back and broke F_DUPFD_CLOEXEC (making it behave like
plain F_DUPFD), so it might be necessary to add some additional fixup
code later to deal with that issue too.
remove __SYSCALL_SSLEN arch macro in favor of using public _NSIG

the issue at hand is that many syscalls require as an argument the
kernel-ABI size of sigset_t, intended to allow the kernel to switch to
a larger sigset_t in the future. previously, each arch was defining
this size in syscall_arch.h, which was redundant with the definition
of _NSIG in bits/signal.h. as it's used in some not-quite-portable
application code as well, _NSIG is much more likely to be recognized
and understood immediately by someone reading the code, and it's also
shorter and less cluttered.

note that _NSIG is actually 65/129, not 64/128, but the division takes
care of throwing away the off-by-one part.
implement pthread_getattr_np

this function is mainly (purely?) for obtaining stack address
information, but we also provide the detach state since it's easy to
do anyway.