GeezerVison

Add primitives for == / != where both operands are list, or both are variable-length tuple (tuple[T, ...]).

Previously these used PyObject_RichCompare, followed by a truth test of the returned object. The new CPyList_Compare / CPyTuple_Compare take the operator (Py_EQ or Py_NE) and return a C int directly (like CPyBytes_Compare):

• If both objects are exact list / tuple objects: identical objects are equal, otherwise items are compared with PyObject_RichCompareBool, like CPython does. Lists of different lengths are not equal without comparing items. Tuples compare items even if the lengths differ, since CPython's tuple comparison doesn't have a length shortcut (item comparisons can have side effects or raise exceptions).
• CPyList_Compare holds a critical section on both lists (like CPython), and handles lists being mutated by an item __eq__.
• Subclasses (which may override __eq__ or __ne__) use PyObject_RichCompare with the original operator, so != calls __ne__ instead of negating __eq__.

Fixed-length tuples (RTuple) are already compared item by item, so they are not affected.

Tests compare the results against the generic implementation (through Any), and cover items with custom __eq__ (including non-bool results and exceptions), identity of items (NaN), mutation during comparison, tuples of different lengths, and subclasses (including named tuples, and subclasses overriding only __eq__ or only __ne__).

Micro-benchmark (compiled code, 3.2M comparisons, best of 15, before -> after, Python 3.13):

Part of mypyc/mypyc#644.