These are equivalent to `zend_hash_clean()` and `zend_hash_destroy()`
respectively, but take care of correctly unregistering the weak references to
the keys.
This addition rounds off the weakmap functionality added in
471102edcd by taking one possible footgun away
from the user.
Shift pointers by ZEND_MM_ALIGNMENT_LOG2
to avoid the noticeable performance degradation caused by hash table collisions.
in `EG(weakrefs)` and zend_weakmap->ht
On 64-bit platforms, pointers are usually aligned to at least 8 bytes,
so only one in 8 hash buckets were actually getting used.
(With the metadata needed to track allocations,
alignment might be at least 16 bytes in practice)
Address review comments, add optimization
Make it public for any extensions that need to work with EG(weakrefs)
for instrumentation, debugging, etc. (e.g. zend_test)
PHP 8.1 and previous releases would use the raw pointer value as a hash key instead.
