I'm not at all sure what I was thinking when I designed it, but I
certainly designed it wrong (to the point of being fairly useless). It
turns out memory requirements are already aligned in size (so just
multiplying is fine), and what I really wanted was to get the next
offset aligned to the given requirements.
When allocating memory for multiple objects that have alignment
requirements, it gets tedious keeping track of the offset and the
alignment. This is a simple function for walking the offset respecting
size and alignment requirements, and doubles as a size calculator.
