casted to structs by getting rid of these buffers entirely. In r169832, it
was tried to paper over this issue by 32-bit aligning the buffers. Depending
on compiler optimizations that still was insufficient for 64-bit architectures
with strong alignment requirements though.
While at it, add comments regarding the total lack of locking in this area.
Tested by: bz
Reviewed by: bz (slightly earlier version), yongari (earlier version)
MFC after: 1 week