Fix GH-23842: skipLazyInitialization() copies unresolved constant defaults

[lazerg]

Fixes GH-23842.

skipLazyInitialization() reads the property default straight out of ce->default_properties_table. Under shared-memory opcache the class entry is immutable and a default that references a class constant stays an unresolved AST there; the resolved value lives in the class's mutable data. So the method copied an IS_CONSTANT_AST zval into the object slot, and the property then held something that is not a valid value of its declared type. var_dump() on it prints UNKNOWN:0, and a typed return over it throws a TypeError.

CE_DEFAULT_PROPERTIES_TABLE() picks the mutable table when there is one, which is what the rest of the lazy object code already does in zend_lazy_object_mark_as_initialized() and zend_lazy_object_init(). property_get_default() still reads the raw field, but getDefaultValue() resolves the AST afterwards, so it is not affected.

The diagnosis and the one-line patch are DirkTrunkstar's, from the issue.

[ndossche]

Okay, but note I will add the issue's OP as first author