Patched match expression to work with the new grammar.
Changed ZEND_FETCH_DEFAULT_ARG VM handler to use reflection_parameter_ptr.

Exposed get_parameter_default from reflection API.

Added exception handling for passing `default` to required parameters.
Fixed default_value leak in ZEND_FETCH_DEFAULT_ARG handler.

Added compile-time exclusion for default in non-argument contexts.

Added tests for anonymous classes, callables and closures.

Added test for default with variadic arguments.