gh-117431: Adapt bytes and bytearray .find() and friends to Argument Clinic (#117502)

This change gives a significant speedup, as the METH_FASTCALL calling
convention is now used. The following bytes and bytearray methods are adapted:

- count()
- find()
- index()
- rfind()
- rindex()

Co-authored-by: Inada Naoki <songofacandy@gmail.com>

Objects/stringlib/find.h

@@ -70,50 +70,3 @@ STRINGLIB(contains_obj)(PyObject* str, PyObject* sub)
 }
 
 #endif /* STRINGLIB_WANT_CONTAINS_OBJ */
-
-/*
-This function is a helper for the "find" family (find, rfind, index,
-rindex) and for count, startswith and endswith, because they all have
-the same behaviour for the arguments.
-
-It does not touch the variables received until it knows everything
-is ok.
-*/
-
-#define FORMAT_BUFFER_SIZE 50
-
-Py_LOCAL_INLINE(int)
-STRINGLIB(parse_args_finds)(const char * function_name, PyObject *args,
-                           PyObject **subobj,
-                           Py_ssize_t *start, Py_ssize_t *end)
-{
-    PyObject *tmp_subobj;
-    Py_ssize_t tmp_start = 0;
-    Py_ssize_t tmp_end = PY_SSIZE_T_MAX;
-    PyObject *obj_start=Py_None, *obj_end=Py_None;
-    char format[FORMAT_BUFFER_SIZE] = "O|OO:";
-    size_t len = strlen(format);
-
-    strncpy(format + len, function_name, FORMAT_BUFFER_SIZE - len - 1);
-    format[FORMAT_BUFFER_SIZE - 1] = '\0';
-
-    if (!PyArg_ParseTuple(args, format, &tmp_subobj, &obj_start, &obj_end))
-        return 0;
-
-    /* To support None in "start" and "end" arguments, meaning
-       the same as if they were not passed.
-    */
-    if (obj_start != Py_None)
-        if (!_PyEval_SliceIndex(obj_start, &tmp_start))
-            return 0;
-    if (obj_end != Py_None)
-        if (!_PyEval_SliceIndex(obj_end, &tmp_end))
-            return 0;
-
-    *start = tmp_start;
-    *end = tmp_end;
-    *subobj = tmp_subobj;
-    return 1;
-}
-
-#undef FORMAT_BUFFER_SIZE