CLR arrays don't support negative indexing

[antonsynd]

Problem

CLR arrays (array[T]) don't support Python-style negative indexing. arr[-1] throws IndexOutOfRangeException instead of returning the last element.

Sharpy lists handle this via wrapper methods in Sharpy.Core, but CLR arrays use native .NET array indexing which doesn't have this support.

Reproduction

def main():
    arr: array[int] = array[int](3)
    arr[0] = 10
    arr[1] = 20
    arr[2] = 30
    print(arr[-1])  # should print 30
    print(arr[-2])  # should print 20

Expected output:

30
20

Actual: IndexOutOfRangeException at runtime.

Possible Approach

Add a Sharpy.Core wrapper or extension method for array indexing that normalizes negative indices.

Skipped Test

TestFixtures/arrays/array_negative_index.spy — skip reason: "CLR arrays don't support negative indexing natively; needs Sharpy.Core wrapper"