bpo-40275: Use new test.support helper submodules in tests (GH-21315)

Lib/test/test_picklebuffer.py

diff --git a/Lib/test/test_picklebuffer.py b/Lib/test/test_picklebuffer.py
index 97981c8..435b3e0 100644
--- a/Lib/test/test_picklebuffer.py
+++ b/Lib/test/test_picklebuffer.py
@@ -8,7 +8,7 @@
 import weakref
 import unittest
 
-from test import support
+from test.support import import_helper
 
 
 class B(bytes):
@@ -75,7 +75,7 @@
 
     def test_ndarray_2d(self):
         # C-contiguous
-        ndarray = support.import_module("_testbuffer").ndarray
+        ndarray = import_helper.import_module("_testbuffer").ndarray
         arr = ndarray(list(range(12)), shape=(4, 3), format='<i')
         self.assertTrue(arr.c_contiguous)
         self.assertFalse(arr.f_contiguous)
@@ -109,7 +109,7 @@
 
     def test_raw_ndarray(self):
         # 1-D, contiguous
-        ndarray = support.import_module("_testbuffer").ndarray
+        ndarray = import_helper.import_module("_testbuffer").ndarray
         arr = ndarray(list(range(3)), shape=(3,), format='<h')
         equiv = b"\x00\x00\x01\x00\x02\x00"
         self.check_raw(arr, equiv)
@@ -135,7 +135,7 @@
 
     def test_raw_non_contiguous(self):
         # 1-D
-        ndarray = support.import_module("_testbuffer").ndarray
+        ndarray = import_helper.import_module("_testbuffer").ndarray
         arr = ndarray(list(range(6)), shape=(6,), format='<i')[::2]
         self.check_raw_non_contiguous(arr)
         # 2-D