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/Lib/importlib/test/benchmark.py b/Lib/importlib/test/benchmark.py
index 1686314..183e818 100644
--- a/Lib/importlib/test/benchmark.py
+++ b/Lib/importlib/test/benchmark.py
@@ -9,7 +9,6 @@
 import decimal
 import imp
 import importlib
-import importlib._bootstrap
 import importlib.machinery
 import json
 import os
@@ -72,7 +71,7 @@
             assert not os.path.exists(imp.cache_from_source(mapping[name]))
             sys.meta_path.append(importlib.machinery.PathFinder)
             loader = (importlib.machinery.SourceFileLoader,
-                      importlib._bootstrap._SOURCE_SUFFIXES, True)
+                      importlib.machinery.SOURCE_SUFFIXES, True)
             sys.path_hooks.append(importlib.machinery.FileFinder.path_hook(loader))
             for result in bench(name, lambda: sys.modules.pop(name), repeat=repeat,
                                 seconds=seconds):
@@ -110,7 +109,7 @@
     with source_util.create_modules(name) as mapping:
         sys.meta_path.append(importlib.machinery.PathFinder)
         loader = (importlib.machinery.SourceFileLoader,
-                  importlib._bootstrap._SOURCE_SUFFIXES, True)
+                  importlib.machinery.SOURCE_SUFFIXES, True)
         sys.path_hooks.append(importlib.machinery.FileFinder.path_hook(loader))
         def cleanup():
             sys.modules.pop(name)
@@ -145,7 +144,7 @@
     with source_util.create_modules(name) as mapping:
         sys.meta_path.append(importlib.machinery.PathFinder)
         loader = (importlib.machinery.SourceFileLoader,
-                importlib._bootstrap._SOURCE_SUFFIXES, True)
+                importlib.machinery.SOURCE_SUFFIXES, True)
         sys.path_hooks.append(importlib.machinery.FileFinder.path_hook(loader))
         py_compile.compile(mapping[name])
         assert os.path.exists(imp.cache_from_source(mapping[name]))