bpo-39301: State that floor division is used for right shift operations (GH-20347) (GH-20414)

* bpo-39301: State that floor division is used for right shift operations

* Remove "without overflow check"
(cherry picked from commit af7553ac95a96713be847dd45bc5a8aeb0a75955)

Co-authored-by: Zackery Spytz <zspytz@gmail.com>

Co-authored-by: Zackery Spytz <zspytz@gmail.com>
diff --git a/Doc/library/stdtypes.rst b/Doc/library/stdtypes.rst
index 4e7729c..6a9fdcb 100644
--- a/Doc/library/stdtypes.rst
+++ b/Doc/library/stdtypes.rst
@@ -434,12 +434,10 @@
    Negative shift counts are illegal and cause a :exc:`ValueError` to be raised.
 
 (2)
-   A left shift by *n* bits is equivalent to multiplication by ``pow(2, n)``
-   without overflow check.
+   A left shift by *n* bits is equivalent to multiplication by ``pow(2, n)``.
 
 (3)
-   A right shift by *n* bits is equivalent to division by ``pow(2, n)`` without
-   overflow check.
+   A right shift by *n* bits is equivalent to floor division by ``pow(2, n)``.
 
 (4)
    Performing these calculations with at least one extra sign extension bit in