floooh
Allow invalid regs
This thread at World of Spectrum says that it's valid to write to invalid AY registers, and that you can read back the value, which decays over time.
This PR doesn't implement the decay, but makes it possible to set the register address to an invalid one, and makes reading back from it return 0, as if it instantly decays.
I made this change because there's this SZX snapshot that has the last AY register address set to 16, and it was causing an assert. Instead of making it a special case in my code, I thought it would be nice if it was at least partially implemented in ay38910.h.
Thanks, I'll try to look in detail into the PR 'soon-ish'...
In the meantime, don't mind the CI errors, looks like those are unrelated to your PR (I guess trying to use designated initialization in the C++ code was a mistake lol - not sure why those problems haven't shown up earlier though).
Yeah I saw that some passed and thought the errors shouldn't be related to my changes.