From: Jesse Gross <redacted>
Date: Fri, 30 Aug 2013 16:20:25 -0700

I looked through the struct definition and I think that the idea of
manually padding as Geert did in his patch will be difficult to
maintain over time (and actually there are a few that he missed) since
there are a number of different structs/unions contained in there.

You have to be mindful of the gaps and wasted space for performance
reasons anyways.