loader: enable subtests filter for simple tests

Simple tests discovery is not considering the subtests filter.

This patch adds to the simple test discovery process the capability of
filtering the tests by subtests filter.
Signed-off-by: NAmador Pahim <apahim@redhat.com>

avocado/core/loader.py

@@ -877,7 +877,8 @@ class FileLoader(TestLoader):
                 if os.access(test_path, os.X_OK):
                     # Module does not have an avocado test class inside but
                     # it's executable, let's execute it.
-                    return self._make_test(test.SimpleTest, test_path)
+                    return self._make_test(test.SimpleTest, test_path,
+                                           subtests_filter=subtests_filter)
                 else:
                     # Module does not have an avocado test class inside, and
                     # it's not executable. Not a Test.
@@ -893,18 +894,23 @@ class FileLoader(TestLoader):
             if os.access(test_path, os.X_OK):
                 # Module can't be imported, and it's executable. Let's try to
                 # execute it.
-                return self._make_test(test.SimpleTest, test_path)
+                return self._make_test(test.SimpleTest, test_path,
+                                       subtests_filter=subtests_filter)
             else:
                 return make_broken(NotATest, test_path, self.__not_test_str)
 
     @staticmethod
-    def _make_test(klass, uid, description=None):
+    def _make_test(klass, uid, description=None, subtests_filter=None):
         """
         Create test template
         :param klass: test class
         :param uid: test uid (by default used as id and name)
         :param description: Description appended to "uid" (for listing purpose)
+        :param subtests_filter: optional filter of methods for avocado tests
         """
+        if subtests_filter and not subtests_filter.search(uid):
+            return []
+
         if description:
             uid = "%s: %s" % (uid, description)
         return [(klass, {'name': uid})]
@@ -934,8 +940,8 @@ class FileLoader(TestLoader):
                                                       subtests_filter)
             else:
                 if os.access(test_path, os.X_OK):
-                    return self._make_test(test.SimpleTest,
-                                           test_path)
+                    return self._make_test(test.SimpleTest, test_path,
+                                           subtests_filter=subtests_filter)
                 else:
                     return make_broken(NotATest, test_path,
                                        self.__not_test_str)