Suspicious index of rhs element in _check_unpack_assign

[acl-cqc]

guppylang/guppylang/checker/stmt_checker.py

Line 222 in 634e241

unpack.pattern.starred = self._check_assign(starred, rhs_elts[0], array_ty)

uses rhs_elts[0], when the indices that correspond to the starred section are rhs_elts[le:rs]. Not sure whether we should pass the whole range or one element; in many cases all rhs_elts are the same but not if the RHS is a literal tuple.

I played around with many test cases here and couldn't make a program that produced the wrong answer, so I suspect the value here is not used per se - perhaps only for debugging information or something like that?