posix-semaphore egg won't build on OS X: uses deprecated API

[Norman Gray]

Building the posix-semaphore egg fails on OS X, as it uses a deprecated API; see the log below.

This is on OS X 10.11.6, with its associated version of clang (Apple LLVM version 8.0.0 (clang-800.0.42.1)).

It appears to be only the support for unnamed semaphores (which are apparently optional in POSIX) that's deprecated; the support for named ones seems to be present.

There's a StackOverflow? discussion about the deprecation at (1) below, which points to some fairly authoritative discussion, including why the deprecation exists, at (2).

(1) ​http://stackoverflow.com/questions/27736618/why-are-sem-init-sem-getvalue-sem-destroy-deprecated-on-mac-os-x-and-w
(2) ​https://lists.apple.com/archives/darwin-kernel/2009/Apr/msg00010.html

% chicken-install posix-semaphore
retrieving ...
connecting to host "chicken.kitten-technologies.co.uk", port 80 ...
requesting "/henrietta.cgi?name=posix-semaphore&mode=default" ...
reading response ...
HTTP/1.1 200 OK
Date: Mon, 13 Mar 2017 23:30:47 GMT
Server: Apache/2.2.31 (Unix) DAV/2 PHP/5.5.36 mod_fastcgi/2.4.6
Connection: close
Transfer-Encoding: chunked
Content-Type: text/plain
reading chunks .
reading files ...
  ./readme.md
  ./LICENSE
  ./posix-semaphore.release-info
  ./posix-semaphore.meta
  ./posix-semaphore.setup
  ./posix-semaphore.scm
  ./test.scm
 posix-semaphore located at /var/folders/7b/1fldmb290mzbgxppkpwwffx40000gn/T/temp3c46.40550/posix-semaphore
checking platform for `posix-semaphore' ...
checking dependencies for `posix-semaphore' ...
install order:
("posix-semaphore")
installing posix-semaphore:0.5.1 ...
changing current directory to /var/folders/7b/1fldmb290mzbgxppkpwwffx40000gn/T/temp3c46.40550/posix-semaphore
  '/Data/tools/chicken-4.12/bin/csi' -bnq -setup-mode -e "(require-library setup-api)" -e "(import setup-api)" -e "(setup-error-handling)" -e "(extension-name-and-version '(\"posix-semaphore\" \"0.5.1\"))" 'posix-semaphore.setup'
  '/Data/tools/chicken-4.12/bin/csc' -feature compiling-extension -setup-mode    -O3 -C -O3 -lpthread -s -d1 -j posix-semaphore posix-semaphore.scm
posix-semaphore.c:63:11: warning: 'sem_getvalue' is deprecated [-Wdeprecated-declarations]
int err = sem_getvalue(sem, &val);
          ^
/usr/include/sys/semaphore.h:54:5: note: 'sem_getvalue' has been explicitly marked
      deprecated here
int sem_getvalue(sem_t * __restrict, int * __restrict) __deprecated;
    ^
posix-semaphore.c:92:1: warning: implicit declaration of function 'clock_gettime' is
      invalid in C99 [-Wimplicit-function-declaration]
clock_gettime(CLOCK_REALTIME, &tm);
^
posix-semaphore.c:92:15: error: use of undeclared identifier 'CLOCK_REALTIME'
clock_gettime(CLOCK_REALTIME, &tm);
              ^
posix-semaphore.c:95:7: warning: implicit declaration of function 'sem_timedwait' is
      invalid in C99 [-Wimplicit-function-declaration]
CHECK(sem_timedwait(sem, &tm))
      ^
posix-semaphore.c:180:7: warning: 'sem_destroy' is deprecated [-Wdeprecated-declarations]
CHECK(sem_destroy(sem))
      ^
/usr/include/sys/semaphore.h:53:5: note: 'sem_destroy' has been explicitly marked
      deprecated here
int sem_destroy(sem_t *) __deprecated;
    ^
posix-semaphore.c:192:7: warning: 'sem_init' is deprecated [-Wdeprecated-declarations]
CHECK(sem_init(sem, shared, value))
      ^
/usr/include/sys/semaphore.h:55:5: note: 'sem_init' has been explicitly marked deprecated
      here
int sem_init(sem_t *, int, unsigned int) __deprecated;
    ^
5 warnings and 1 error generated.

Error: shell command terminated with non-zero exit status 256: '/Applications/Xcode.app/Contents/Developer/usr/bin/gcc' 'posix-semaphore.c' -o 'posix-semaphore.o' -c  -fno-strict-aliasing -fwrapv -fno-common -DHAVE_CHICKEN_CONFIG_H -m64 -DC_ENABLE_PTABLES -Os -fomit-frame-pointer -fPIC -DPIC -DC_SHARED -O3 -I/Data/tools/chicken-4.12/include/chicken

Error: shell command failed with nonzero exit status 256:

  '/Data/tools/chicken-4.12/bin/csc' -feature compiling-extension -setup-mode    -O3 -C -O3 -lpthread -s -d1 -j posix-semaphore posix-semaphore.scm


Error: shell command terminated with nonzero exit code
17920
"'/Data/tools/chicken-4.12/bin/csi' -bnq -setup-mode -e \"(require-library setup...