Fix zend_get_property_info_for_slot() for lazy objects

[arnaud-lb]

zend_get_property_info_for_slot(obj, slot) assumes that 'slot' belongs to 'obj', but that may not be the case for lazy proxies.

Fortunatley, the property info is often already available in path when it is nedded.

For other cases, I make zend_get_property_info_for_slot() aware of lazy objects, and add zend_get_property_info_for_slot_self() for cases where the 'slot' is known to belong to the object itself.

Fixes oss-fuzz #71446

VM uses zend_get_property_info_for_slot() for variable property accesses such as $obj->$prop. I retrieve the property info by inspecting the cache_slot, as it's set by the read_property or get_property_ptr_ptr handlers. An alternative would be to add a zend_property_info ** parameter to these handlers.

[dstogov]

I don't understand this in all details, but I think it's OK.

[dstogov]

How does this change the cost for non CONST op2?
On one hand now get_property_ptr_ptr has to make more work, on the other hand zend_object_fetch_property_type_info is eliminated.
Can you measure the difference, please.

[arnaud-lb]

With this micro bench under callgrind:

<?php

class C {
    public int $a = 0;
}

$obj = new C();
$a = 'a';
for ($i = 0; $i < 1_000_000; $i++) {
    $obj->$a += 2;
}

base:  mean:  264465884.0000;  stddev:  0.0000;  diff:  +0.00%
pr:    mean:  250464574.0000;  stddev:  0.0000;  diff:  -5.29%
alt:   mean:  246467362.0000;  stddev:  0.0000;  diff:  -6.81%

pr is this branch, and alt is an alternative in which I added a zend_property_info **prop_info_p parameter to zend_object_read_property_t and zend_object_get_property_ptr_ptr_t.

alt is faster than pr for op2 != CONST, however it's slower for op2 = CONST:

<?php

class C {
    public int $a = 0;
}

$obj = new C();
for ($i = 0; $i < 1_000_000; $i++) {
    $obj->a += 2;
}

base:  mean:  192463206.0000;  stddev:  0.0000;  diff:  +0.00%
pr:    mean:  192461896.0000;  stddev:  0.0000;  diff:  -0.00%
alt:   mean:  196464687.0000;  stddev:  0.0000;  diff:  +2.08%