Patch #830858: Correct the number of is-functions. Backported to 2.3 and 2.2.

Doc/lib/libinspect.tex

@@ -25,7 +25,7 @@ and functions, and examining the interpreter stack.
 
 The \function{getmembers()} function retrieves the members
 of an object such as a class or module.
-The nine functions whose names begin with ``is'' are mainly
+The eleven functions whose names begin with ``is'' are mainly
 provided as convenient choices for the second argument to
 \function{getmembers()}.  They also help you determine when
 you can expect to find the following special attributes:

Lib/test/test_inspect.py

@@ -370,3 +370,7 @@ test(args == ['self'], 'A.m args')
 test(varargs is None, 'A.m varargs')
 test(varkw is None, 'A.m varkw')
 test(defaults is None, 'A.m defaults')
+
+# Doc/lib/libinspect.tex claims there are 11 such functions
+count = len(filter(lambda x:x.startswith('is'), dir(inspect)))
+test(count == 11, "There are %d (not 11) is* functions", count)