Fix VC compilation as variable size array is not supported

Author: weltling

ext/mysqlnd/mysqlnd_wireprotocol.c

@@ -2277,7 +2277,12 @@ size_t php_mysqlnd_cached_sha2_result_write(void * _packet)
 	MYSQLND_PFC * pfc = packet->header.protocol_frame_codec;
 	MYSQLND_VIO * vio = packet->header.vio;
 	MYSQLND_STATS * stats = packet->header.stats;
+#ifndef _MSC_VER
 	zend_uchar buffer[MYSQLND_HEADER_SIZE + packet->password_len + 1];
+#else
+	ALLOCA_FLAG(use_heap)
+	zend_uchar *buffer = do_alloca(MYSQLND_HEADER_SIZE + packet->password_len + 1, use_heap);
+#endif
 	size_t sent;
 
 	DBG_ENTER("php_mysqlnd_cached_sha2_result_write");
@@ -2290,6 +2295,10 @@ size_t php_mysqlnd_cached_sha2_result_write(void * _packet)
 		sent = pfc->data->m.send(pfc, vio, buffer, packet->password_len, stats, error_info);
 	}
 
+#ifdef _MSC_VER
+	free_alloca(buffer, use_heap);
+#endif
+
 	DBG_RETURN(sent);
 }