Align PCE emulator to the original ducalex retrogo (for possible gain of 40% performance)

[Macs75]

In particular the request would be to cherry pick at least this commit that is described to have improved up to 40% the performances:

https://github.com/ducalex/retro-go/commit/d51e90315cbe4ac38fe5a0aff05be2d47d76e712#diff-f3099ff86b89ff6d7a633d01bd6d586317d1fde8efc43eccfcf0f39f5628c85d