HighwaySegment size & alignment

[yakra]

The implementation of TMBitset will make sizeof(HighwaySegment) ~128~ 112. Ergo, it will be a good candidate for alignas(64).

What tasks iterate through these? How do they perform?

TMArray: https://en.cppreference.com/w/c/memory/aligned_alloc or new operator

[yakra]

Could conceivably get as low as 48 B:

• *waypoint1 and *waypoint2 could be replaced with functions after Waypoint and HighwaySegment objects are stored sequentially in their Route.
• *`route`** is necessary.
• double length can be calculated on the fly -- I forget how much time store+retrieve saved in C++
• *`concurrent`** is necessary.
• clinched_by is necessary.
• clin_mtx could go bye-bye.

Add uint32_t collap_span, travel_span; in order to collapse the HGEdge class into HighwaySegment and we're still at 56 B, < 1 cache line.