Regression in [0] changed the order of execution for the load_post
handler which previously (in 3.5x) ran before driver evaluation.
Calling either load_post/load_post_fail handlers after loading was
changed intentionally to simplify the code-path for calling handlers
however it meant the handler couldn't be used to setup drivers,
so restore the original logic.
[0]: 46be42f6b1
c6725b935c