When I build a cocos2d-x project used the latest github version ,It show me this.Than I include “SimpleAudioEngine.h” and replace the SimpleAudioEngine to CocosDenshion::SimpleAudioEngine .It was solved.
use #include "SimpleAudioEngine.h" at the top of your cpp file.
Hope this helps.
I know you have mentioned the answer in the question, but generally no one looks for answer in the question. So I posted this as an answer.