Make size of TOS cache configurable

TOS caching was introduced by https://github.com/python/cpython/issues/135379, but it only supports a fixed number of registers.
We should make it configurable, so that we can choose the optimum number of registers for any hardware/OS combination.

Probably the simplest way to do this is to generate executor cases and stencils code for up to the overall maximum number of registers, and guard each case/function with an #if MAX_CACHED_REGISTER > N where N is the number of registers needed for that variant.
Some cases/functions will also need to guarded for when MAX_CACHED_REGISTER is too low.

For example the ideal number of output registers for _BINARY_OP variants is 3.
For machines where MAX_CACHED_REGISTER < 3, we will need to generate variants with outputs < 3, but we want to exclude those variants for machines with MAX_CACHED_REGISTER >= 3

Overall this could result in generating a lot more code, probably more than double, but if MAX_CACHED_REGISTER is unchanged then the executable size should also be unchanged.

If we increase the MAX_CACHED_REGISTER to 4 or 5 we would expect the stencils and supporting tables to increase by ~35% and ~80% respectively (growth being a bit more than linear as some instructions have N**2 variants)

Linked PRs

• gh-145830

Commencez par lire l’issue 135379 et le travail associé dans la PR 145830, puis suivez les chemins de génération des registres et du stencil du cache TOS décrits ici. Le travail est terminé lorsque MAX_CACHED_REGISTER peut sélectionner des variantes adaptées à différentes combinaisons de matériel et de système d’exploitation, tout en préservant le comportement indiqué de la taille de l’exécutable lorsqu’elle reste inchangée.