For any methods or function which are meant to always throw exception or exit the code using things like: exit() or
die() a new return type of:
noreturn was added. The sample usage could be:
function iWillAlwaysExit(): noreturn .
Added a new check to
array to see if it contains only an int based keys in natural order (from 0 to n`). Useful when we want to ensure the array is consistent (untouched) and when we want to serialize an
json to format of
[0, 1, 2] instead of object properties.