Add __ON_CONSTRUCT__ and similar

[petergjoel]

Documentation on __ON_CONSTRUCT__ and similar from https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=8292158 is missing.

Also the ptr_t declaration would probably be handy/should be build in.

[mikucionisaau]

Fixed with the following extra sections:
Special Functions
Resources

I cannot find any implementation traces about ptr_t

[petergjoel]

The ptr_t (as I recall) was omitted from the implementation. I envisioned it as being defined in some "stdlib". Any two int struct can be used as a ptr_t (for 64 bit arch). The ranges should be full int32_t of either.