OS/2: Fix building of more modules that depend on symbols from other modules.

Affected modules are: mod_heartbeat, mod_session_cookie, mod_session_crypto,
mod_session_dbd and mod_disk_cache.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@956857 13f79535-47bb-0310-9956-ffa450edef68