[build] compile fixes for AIX

x-ref:
  https://www.lighttpd.net/2016/10/31/1.4.43/  (see comments section)

src/mod_authn_file.c

@@ -641,7 +641,11 @@ static handler_t mod_authn_file_htpasswd_basic(server *srv, connection *con, voi
             char *crypted;
            #if defined(HAVE_CRYPT_R)
             struct crypt_data crypt_tmp_data;
+            #ifdef _AIX
+            memset(&crypt_tmp_data, 0, sizeof(crypt_tmp_data));
+            #else
             crypt_tmp_data.initialized = 0;
+            #endif
            #endif
            #ifdef USE_OPENSSL /* (for MD4_*() (e.g. MD4_Update())) */
             if (0 == memcmp(password->ptr, CONST_STR_LEN("$1+ntlm$"))) {

src/mod_authn_mysql.c

@@ -342,7 +342,11 @@ static int mod_authn_mysql_password_cmp(const char *userpw, unsigned long userpw
             char *crypted;
           #if defined(HAVE_CRYPT_R)
             struct crypt_data crypt_tmp_data;
+           #ifdef _AIX
+            memset(&crypt_tmp_data, 0, sizeof(crypt_tmp_data));
+           #else
             crypt_tmp_data.initialized = 0;
+           #endif
           #endif
             memcpy(salt, saltb, slen);
             salt[slen] = '\0';

src/mod_cgi.c

@@ -36,7 +36,7 @@
 #include <fcntl.h>
 
 #if defined(O_CLOEXEC) && (!defined(__FreeBSD__) || defined(SOCK_CLOEXEC)) \
- && !(defined(__APPLE__) && defined(__MACH__))
+ && !defined(_AIX) && !(defined(__APPLE__) && defined(__MACH__))
 #define pipe_cloexec(pipefd) pipe2((pipefd), O_CLOEXEC)
 #elif defined FD_CLOEXEC
 #define pipe_cloexec(pipefd) \