Add sanity import test to ansible-test. (#26730)

* Add sanity import test to ansible-test.
* Run sanity import test on all python versions.

test/runner/importer.py

@@ -0,0 +1,49 @@
+#!/usr/bin/env python
+"""Import the given python module(s) and report error(s) encountered."""
+
+from __future__ import absolute_import, print_function
+
+import imp
+import os
+import sys
+import traceback
+
+
+def main():
+    """Main program function."""
+    base_dir = os.getcwd()
+    messages = set()
+
+    for path in sys.argv[1:]:
+        try:
+            with open(path, 'r') as module_fd:
+                imp.load_module('module_import_test', module_fd, os.path.abspath(path), ('.py', 'r', imp.PY_SOURCE))
+        except Exception as ex:  # pylint: disable=locally-disabled, broad-except
+            exc_type, _, exc_tb = sys.exc_info()
+            message = str(ex)
+            results = list(reversed(traceback.extract_tb(exc_tb)))
+            source = None
+            line = None
+
+            for result in results:
+                if result[0].startswith(base_dir):
+                    source = result[0][len(base_dir) + 1:].replace('test/runner/import/', '')
+                    line = result[1]
+                    break
+
+            if not source:
+                source = path
+                line = 0
+                message += ' (in %s:%d)' % (results[-1][0], results[-1][1])
+
+            error = '%s:%d:0: %s: %s' % (source, line, exc_type.__name__, message)
+
+            if error not in messages:
+                messages.add(error)
+                print(error)
+
+    if messages:
+        exit(10)
+
+if __name__ == '__main__':
+    main()