code_richcompare() now uses the constants types

Issue #25843: When compiling code, don't merge constants if they are equal but
have a different types. For example, "f1, f2 = lambda: 1, lambda: 1.0" is now
correctly compiled to two different functions: f1() returns 1 (int) and f2()
returns 1.0 (int), even if 1 and 1.0 are equal.

Add a new _PyCode_ConstantKey() private function.

Include/code.h

@@ -108,12 +108,21 @@ typedef struct _addr_pair {
         int ap_upper;
 } PyAddrPair;
 
+#ifndef Py_LIMITED_API
 /* Update *bounds to describe the first and one-past-the-last instructions in the
    same line as lasti.  Return the number of that line.
 */
-#ifndef Py_LIMITED_API
 PyAPI_FUNC(int) _PyCode_CheckLineNumber(PyCodeObject* co,
                                         int lasti, PyAddrPair *bounds);
+
+/* Create a comparable key used to compare constants taking in account the
+ * object type. It is used to make sure types are not coerced (e.g., float and
+ * complex) _and_ to distinguish 0.0 from -0.0 e.g. on IEEE platforms
+ *
+ * Return (type(obj), obj, ...): a tuple with variable size (at least 2 items)
+ * depending on the type and the value. The type is the first item to not
+ * compare bytes and str which can raise a BytesWarning exception. */
+PyAPI_FUNC(PyObject*) _PyCode_ConstantKey(PyObject *obj);
 #endif
 
 PyAPI_FUNC(PyObject*) PyCode_Optimize(PyObject *code, PyObject* consts,