Rename+move zend_hash_apply_deleter and reuse it

Rename+move zend_hash_apply_deleter and reuse it

The interruption handling was normalized to wrap the entire deletion
operation (instead of leaving out the destructor call and/or the
deallocation) per the recommendation of somebody (don't remember who)
familiar with zend signals.

There is an always-inlined variant of the function for use in
the main deletion function, to ensure there is no performance
impact.