Issue #13959: Deprecate imp.get_suffixes() for new attributes on
importlib.machinery that provide the suffix details for import.
The attributes were not put on imp so as to compartmentalize
everything importlib needs for setting up imports in
importlib.machinery.

This also led to an indirect deprecation of inspect.getmoduleinfo() as
it directly returned imp.get_suffix's returned tuple which no longer
makes sense.
diff --git a/Doc/library/imp.rst b/Doc/library/imp.rst
index 1345b25..7270e3c 100644
--- a/Doc/library/imp.rst
+++ b/Doc/library/imp.rst
@@ -30,6 +30,9 @@
    :const:`PY_SOURCE`, :const:`PY_COMPILED`, or :const:`C_EXTENSION`, described
    below.
 
+   .. deprecated:: 3.3
+      Use the constants defined on :mod:`importlib.machinery` instead.
+
 
 .. function:: find_module(name[, path])