Add missing imports

Author: vstinner

Lib/test/libregrtest/skipped.py

@@ -293,6 +293,7 @@ def expected_to_be_skipped(test_name):
 
     if test_name == 'test_asdl_parser':
         # Test only relevant for from-source Python builds
+        import sysconfig
         return not sysconfig.is_python_build()
 
     return False

Lib/test/test_perfmaps.py

@@ -1,6 +1,7 @@
 import os
 import sys
 import unittest
+from test import support
 
 try:
     from _testinternalcapi import perf_map_state_teardown, write_perf_map_entry