bpo-36725: regrtest: add TestResult type (GH-12960)

* Add TestResult and MultiprocessResult types to ensure that results
  always have the same fields.
* runtest() now handles KeyboardInterrupt
* accumulate_result() and format_test_result() now takes a TestResult
* cleanup_test_droppings() is now called by runtest() and mark the
  test as ENV_CHANGED if the test leaks support.TESTFN file.
* runtest() now includes code "around" the test in the test timing
* Add print_warning() in test.libregrtest.utils to standardize how
  libregrtest logs warnings to ease parsing the test output.
* support.unload() is now called with abstest rather than test_name
* Rename 'test' variable/parameter to 'test_name'
* dash_R(): remove unused the_module parameter
* Remove unused imports

1 files changed, 2 insertions, 2 deletions

diff --git a/Lib/test/libregrtest/save_env.py b/Lib/test/libregrtest/save_env.py
index 2313b71..31931f2 100644
--- a/Lib/test/libregrtest/save_env.py
+++ b/Lib/test/libregrtest/save_env.py
@@ -9,6 +9,7 @@ import sysconfig
 import threading
 import warnings
 from test import support
+from test.libregrtest.utils import print_warning
 try:
     import _multiprocessing, multiprocessing.process
 except ImportError:
@@ -283,8 +284,7 @@ class saved_test_environment:
                 self.changed = True
                 restore(original)
                 if not self.quiet and not self.pgo:
-                    print(f"Warning -- {name} was modified by {self.testname}",
-                          file=sys.stderr, flush=True)
+                    print_warning(f"{name} was modified by {self.testname}")
                     print(f"  Before: {original}\n  After:  {current} ",
                           file=sys.stderr, flush=True)
         return False