bpo-35054: Add more index entries for symbols. (GH-10064)

diff --git a/Doc/tutorial/controlflow.rst b/Doc/tutorial/controlflow.rst
index 4bcdafd..f87cd4d 100644
--- a/Doc/tutorial/controlflow.rst
+++ b/Doc/tutorial/controlflow.rst
@@ -526,7 +526,7 @@
 ------------------------
 
 .. index::
-  statement: *
+   single: *; in function calls
 
 Finally, the least frequently used option is to specify that a function can be
 called with an arbitrary number of arguments.  These arguments will be wrapped
@@ -570,7 +570,7 @@
    [3, 4, 5]
 
 .. index::
-  statement: **
+   single: **; in function calls
 
 In the same fashion, dictionaries can deliver keyword arguments with the ``**``\
 -operator::
@@ -675,7 +675,8 @@
 .. sectionauthor:: Zachary Ware <zachary.ware@gmail.com>
 .. index::
    pair: function; annotations
-   single: -> (return annotation assignment)
+   single: ->; function annotations
+   single: :; function annotations
 
 :ref:`Function annotations <function>` are completely optional metadata
 information about the types used by user-defined functions (see :pep:`3107` and