Incorrect behavior of member access on xml with key value < 0

[lasinicl]

Description:
$title.
As per the spec when the evaluated value of the container expression is an xml and and k is < 0, then the evaluation completes abruptly with a panic
(i.e. key-expression is evaluated to get a value k)

But ATM, this result is an empty xml value.

Steps to reproduce:

function init() {
    xml v = xml `This is an xml`;
    io:println(v[-1].toBalString()); // prints xml``, but should panic
}

Affected Versions:
Ballerina 2201.0.2

[github-actions]

This issue is NOT closed with a proper Reason/ label. Make sure to add proper reason label before closing. Please add or leave a comment with the proper reason label now.

      - Reason/EngineeringMistake - The issue occurred due to a mistake made in the past.
      - Reason/Regression - The issue has introduced a regression.
      - Reason/MultipleComponentInteraction - Issue occured due to interactions in multiple components.
      - Reason/Complex - Issue occurred due to complex scenario.
      - Reason/Invalid - Issue is invalid.
      - Reason/Other - None of the above cases.