apcu lead to side effects especially with app management and (soft)
inter-dependencies, and lead also to 500 server errors. While we could
add management to clear apcu cache in many cases (may stil leave edge
cases) the performance benefit is marginally as also class maps are
already cached in opcache. Hence, the simple and effective way to go is
to not use apcu for autoloading.
Signed-off-by: Arthur Schiwon <blizzz@arthur-schiwon.de>