Improve Range Syntax With Negative Values for Taking From the End

To further improve the capabilities of the range syntax, we can expand on that to support the following syntax, where a negative value indicates to count and take values from the end of an array, versus from the beginning

# Syntax for getting the last value?
echo @array[-1]   # Take the next to last value
echo @array[..-1] # Take all but the last value
echo @array[-5..] # Take the last five values
echo @array[-5..-2]