Freed memory trash corruption may cause small performance loss

The following patch:
https://github.com/MariaDB/server/commit/0c188d5efc452b576c46270e65b9db4746ee9dfe

Added TRASH_FREED_MEMORY as a CMAKE option.

It also set TRASH_FREED_MEMORY to AUTO, and thus enabled by default for all non-WIN32, non-VALGRIND and non-ASAN builds (including release builds).

This may result in a small performance loss in release/optimized builds, likely depending on how pronounced memory freeing is.

Sysbench seemed to give different outcomes depending on settings, even an increase of performance once for a high load run (which may have been be skewed due to disk access), though generally with negative outcomes in a range from -0.2% to -1.8% performance.