27.1.23.5 Instruction aref
Synopsys:
Given an array ARR and an index ULONG, push the element of the array
occupying that position on the stack.
If the provided index is out of bounds, then raise
PVM_E_OUT_OF_BOUNDS.
Stack: ( ARR ULONG -- ARR ULONG VAL )
Exceptions: PVM_E_OUT_OF_BOUNDS