it's only in your build. you probably had the driver enabled when it was WIP, and you forgot to remove the line now that it's officially supported
Nice to see it officially added. Though, I would suggest that until more work can be done on it - it would be safer to include a GAME_IMPERFECT_GRAPHICS flag. The 4 games I tried all had issues related to video.. some of which make them quite unplayable.
Rev 5391 adds the anti-alias filtered speaker toggle emulation that was submitted to MAMEdev in May and ignored because it was MESS-only-in-common-code and nobody spoke up for it
It's a noticable difference and I also hooked it up to the Apple II series where it sounds much better and fixes a long-time issue with the mixing on the IIgs (the DC offset from the raw unfiltered speaker toggle was reducing the available headroom for the ES5503).