rts: retainer: Reduce DEBUG_RETAINER ifdef noise
Keeping track of the maximum stack seems like a good idea in all configurations. The associated ASSERTs only materialize in debug mode but having the statistic is nice. To make the debug code less prone to bitrotting I introduce a function 'debug()' which doesn't actually print by default and is #define'd away only when the standard DEBUG define is off.
Showing with 39 additions and 69 deletions