Add zend_call_known_function() API family

[nikic]

This adds the following APIs:

void zend_call_known_function(
    zend_function *fn, zend_object *object, zend_class_entry *called_scope,
    zval *retval_ptr, int param_count, zval *params);

void zend_call_known_instance_method(
    zend_function *fn, zend_object *object, zval *retval_ptr, int param_count, zval *params);
void zend_call_known_instance_method_with_0_params(
    zend_function *fn, zend_object *object, zval *retval_ptr);
void zend_call_known_instance_method_with_1_params(
    zend_function *fn, zend_object *object, zval *retval_ptr, zval *param);
void zend_call_known_instance_method_with_2_params(
    zend_function *fn, zend_object *object, zval *retval_ptr, zval *param1, zval *param2);

These are used to perform a call if you already have the zend_function you want to call. zend_call_known_function() is the base API, the rest are just really thin wrappers around it for the common case of instance method calls.

cc @twose This splits out the part of the zend_call_method functionality that does not require a method name at all.

cc @morrisonlevi I believe you asked me about this at some point.

[twose]

nice, it looks good to me

[Girgias]

Shouldn't the param_count argument be a uint32_t?

[nikic]

Shouldn't the param_count argument be a uint32_t?

Done!

[twose]

Shouldn't the param_count argument be a uint32_t?

Done!

Shouldn't the param_count argument of zend_call_method be a uint32_t too?

[nikic]

@twose I've adjusted the zend_call_method type while merging.

I've also replaced a few more cases where the new function is useful, found by git grep "ZVAL_UNDEF.*function_name". There are still a couple more candidates.