Description:
------------
When compiling the latest php version 5.3.6 with OpenWRT backfire branch, the build fails:
-snip-
ext/standard/php_crypt_r.o: In function `_crypt_extended_init_r':
php_crypt_r.c:(.text+0x4c1): undefined reference to `membar_producer'
php_crypt_r.c:(.text+0x4cf): undefined reference to `atomic_add_int'
collect2: ld returned 1 exit status
make[3]: *** [sapi/cli/php] Error 1
-snap-

When looking into the source file I'm wondering whether the second code path with __sync_fetch_and_add could not be used.

-snip-
#ifdef PHP_WIN32
                InterlockedIncrement(&initialized);
#elif (defined(__GNUC__) && (__GNUC__ >= 4 && __GNUC_MINOR__ >= 2))
                __sync_fetch_and_add(&initialized, 1);
#elif defined(HAVE_ATOMIC_H) /* Solaris 10 defines atomic API within */
                membar_producer();
                atomic_add_int(&initialized, 1);
#endif
-snap-

As gcc compiler version 4.1.2 has support for this function (see http://gcc.gnu.org/onlinedocs/gcc-4.1.2/gcc/Atomic-Builtins.html) I suggest the attached patch to lower the GNUC_MINOR test.

Expected result:
----------------
The build completes as the gcc provided function is used.