bpo-34434: Update doc for bool(), float() and int() arguments (GH-8834)

(cherry picked from commit 3fe89dac42809a7741d50ebf595be98833b79b97)

Co-authored-by: Louis Sautier <sautier.louis@gmail.com>
diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst
index 949a54d..bb47286 100644
--- a/Doc/library/functions.rst
+++ b/Doc/library/functions.rst
@@ -112,6 +112,8 @@
 
    .. index:: pair: Boolean; type
 
+   .. versionchanged:: 3.7
+      *x* is now a positional-only parameter.
 
 .. function:: breakpoint(*args, **kws)
 
@@ -577,6 +579,9 @@
    .. versionchanged:: 3.6
       Grouping digits with underscores as in code literals is allowed.
 
+   .. versionchanged:: 3.7
+      *x* is now a positional-only parameter.
+
 
 .. index::
    single: __format__
@@ -728,7 +733,7 @@
    to provide elaborate line editing and history features.
 
 
-.. class:: int(x=0)
+.. class:: int([x])
            int(x, base=10)
 
    Return an integer object constructed from a number or string *x*, or return
@@ -762,6 +767,9 @@
    .. versionchanged:: 3.6
       Grouping digits with underscores as in code literals is allowed.
 
+   .. versionchanged:: 3.7
+      *x* is now a positional-only parameter.
+
 
 .. function:: isinstance(object, classinfo)