[9.x] Fix method doctypes of Arr class

[hAz5]

Arr::add() support int and float too

$a = Arr::add([], 1, 'hAz');// result: [1 => 'hAz'] FOR INT 
$a = Arr::add([], 1.1, 'hAz');// result: [1 => [1 => 'hAz']] FOR FLOAT

doctype improved.