Cast .with index to a number

Author: nicolo-ribaudo

spec.html

@@ -115,11 +115,10 @@ <h1>Array.prototype.with ( _index_, _value_ )</h1>
                 <emu-alg>
                     1. Let _O_ be the *this* value.
                     1. Let _len_ be ? LengthOfArrayLike(_O_).
-                    1. If IsIntegralNumber(_index_) is *false*, throw a *RangeError* exception.
-                    1. If _index_ &ge; _len_, throw a *RangeError* exception.
-                    1. If _index_ &lt; 0, let _actualIndex_ be _len_ + _index_.
-                    1. Else, let _actualIndex_ be _index_.
-                    1. If _actualIndex_ &lt; 0, throw a *RangeError* exception.
+                    1. Let _relativeIndex_ be ? ToIntegerOrInfinity(_index_).
+                    1. If _index_ &ge; 0, let _actualIndex_ be _relativeIndex_.
+                    1. Else, let _actualIndex_ be _len_ + _relativeIndex_.
+                    1. If _actualIndex_ &ge; _len_ or _actualIndex_ &lt; 0, throw a *RangeError* exception.
                     1. Let _A_ be ? ArrayCreate(𝔽(_len_)).
                     1. Let _k_ be 0.
                     1. Repeat, while _k_ &lt; _len_,