Description:
------------
I'm trying to build PHP 5.4.21 on my Solaris 10 SPARC box, but it's failing when it tries to link in atomic_add_int and membar_producer.  Both of those functions are used in ext/standard/php_crypt_r.c:

 80 void _crypt_extended_init_r(void)
 81 {
 82 #ifdef PHP_WIN32
 83     LONG volatile initialized = 0;
 84 #elif defined(HAVE_ATOMIC_H) /* Solaris 10 defines atomic API within */
 85     volatile unsigned int initialized = 0;
 86 #else
 87     static volatile sig_atomic_t initialized = 0;
 88 #endif
 89 
 90 #ifdef ZTS
 91     tsrm_mutex_lock(php_crypt_extended_init_lock);
 92 #endif
 93 
 94     if (!initialized) {
 95 #ifdef PHP_WIN32
 96         InterlockedIncrement(&initialized);
 97 #elif defined(HAVE_SYNC_FETCH_AND_ADD)
 98         __sync_fetch_and_add(&initialized, 1);
 99 #elif defined(HAVE_ATOMIC_H) /* Solaris 10 defines atomic API within */
100         membar_producer();
101         atomic_add_int(&initialized, 1);
102 #endif
103         _crypt_extended_init();
104     }
105 #ifdef ZTS
106     tsrm_mutex_unlock(php_crypt_extended_init_lock);
107 #endif
108 }

On my version of glibc, atomic_add_int() and membar_producer aren't defined.
$ nm -g /lib/libc.so.1 | grep atomic_add_int
$ nm -g /lib/libc.so.1 | grep membar_producer


Compiler and configuration info:
CFLAGS=""
CPPFLAGS=" -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64"

./configure --disable-cgi --enable-cli --prefix="/path/to/php"
    --with-libxml-dir="/path/to/libxml" --with-openssl=shared,"/path/to/openssl"
    --with-zlib="/path/to/zlib" --with-curl=shared,"/path/to/curl"
    --with-config-file-path=/path/to/cfgfile --with-layout=GNU
    --with-regex=php --with-tsrm-pthreads --disable-rpath --disable-sysvsem --disable-sysvshm
    --disable-sysvmsg --disable-bcmath --disable-ctype --disable-exif --disable-spl --disable-ftp
    --disable-shmop --enable-tokenizer --disable-static --enable-posix=shared --enable-session=shared
    --enable-sockets=shared --enable-xml=shared --enable-pcntl=shared --enable-dom --without-mm
    --without-gettext --without-iconv --without-sqlite --without-mime-magic --without-mysql --without-sybase-ct
    --without-gdbm --without-db4 --without-cdb --without-pear --without-xsl --disable-debug
    --with-pcre-dir="/path/to/pcre" --with-pcre-regex

$ gcc -v
Reading specs from /usr/local/lib/gcc/sparc-sun-solaris2.10/3.4.6/specs
Configured with: ../configure --with-as=/usr/ccs/bin/as --with-ld=/usr/ccs/bin/ld --enable-shared --enable-languages=c,c++,f77
Thread model: posix
gcc version 3.4.6

$ uname -a
SunOS grampa 5.10 Generic sun4u sparc SUNW,Sun-Fire-V210

Snippet from configure output:
checking atomic.h usability... yes
checking atomic.h presence... yes
checking for atomic.h... yes


Expected result:
----------------
Successful linking

Actual result:
--------------
Undefined           first referenced
 symbol                 in file
atomic_add_int                      ext/standard/.libs/php_crypt_r.o
membar_producer                     ext/standard/.libs/php_crypt_r.o
ld: fatal: Symbol referencing errors. No output written to sapi/cli/php
collect2: ld returned 1 exit status
make: *** [sapi/cli/php] Error 1