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.

Lib/importlib/test/source/test_case_sensitivity.py

@@ -1,5 +1,6 @@
 """Test case-sensitivity (PEP 235)."""
 from importlib import _bootstrap
+from importlib import machinery
 from .. import util
 from . import util as source_util
 import imp
@@ -20,12 +21,12 @@ class CaseSensitivityTest(unittest.TestCase):
     assert name != name.lower()
 
     def find(self, path):
-        finder = _bootstrap.FileFinder(path,
-                                        (_bootstrap.SourceFileLoader,
-                                            _bootstrap._SOURCE_SUFFIXES,
+        finder = machinery.FileFinder(path,
+                                      (machinery.SourceFileLoader,
+                                            machinery.SOURCE_SUFFIXES,
                                             True),
-                                        (_bootstrap.SourcelessFileLoader,
-                                            [_bootstrap._BYTECODE_SUFFIX],
+                                        (machinery.SourcelessFileLoader,
+                                            machinery.BYTECODE_SUFFIXES,
                                             True))
         return finder.find_module(self.name)