В результате получил такой код
Array.prototype.splice = function (start, deleteCount) {
var removedArr = [];
var Arr = [];
if (start < 0){
start = this.length + start;
}
for ( var i = start; i <= start + deleteCount-1; i++ ) {
removedArr.push( this[i] );
}
for ( var j = 0; j < start; j++) {
Arr.push(this[j]);
}
for (var a = 2; a <= arguments.length; a++){
if (typeof arguments[a] == 'undefined'){
break;
} else {
Arr.push(arguments[a]);
}
}
for ( var n = start+deleteCount; n < this.length; n++ ) {
Arr.push(this[n])
}
this.length = 0;
this.push.apply(this, Arr);
return removedArr;
};