This reverts commit a7e747c100.
This broke the GitHub Actions automated tests, because they
are using gcc 11 (which does not support level 3 fortification),
and they already predefine another fortification level.
I realize this would also hinder other contributors who
are not using gcc 12. At least I tried it once on my own
system and didn't find any problems, which is nice.
Instead of turning off all "expensive optimizations" in gcc,
I found I can achieve consistent calculation results on
64-bit ARM processors by turning off just the "fp contract"
optimization.
This optimizer is actually supposed to produce *more* accurate
results, but the effect is to produce results that differ
across languages/processors. For the sake of the unit tests,
I have decided it must be turned off in ctest and generate.
It turns out that in gcc 9.3.0 on aarch64, the "expensive optimizations"
were causing incorrect calculations. I resumed using -O3 but with
expensive optimizations turned off. Now all unit tests pass again.
Adding infrastructure for loading TOP2013 models of planets
and calculating them. Will start with a unit test to verify
I'm calculating the formulas correctly.
