As for me, the best way to get error name by int value is that. And it's works fine for me ;)
<?php

array_flip(array_slice(get_defined_constants(true)['Core'], 1, 15, true))[$type];

//the same in readable form
array_flip(
    array_slice(
        get_defined_constants(true)['Core'],
        1,
        15,
        true
    )
)[$type]

?>