ext,tests: Make return code based on test results

This patch also fixes a spelling mistake.

Change-Id: I8635216e512c10913a9cda54541d7e31e0d22a40
Signed-off-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/17450
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>

ext/testlib/handlers.py

@@ -166,6 +166,18 @@ class ResultHandler(log.Handler):
         self._closed = True
         self._save()
 
+    def unsuccessful(self):
+        '''
+        Performs an or reduce on all of the results.
+        Returns true if at least one test is unsuccessful, false when all tests
+        pass
+        '''
+        for suite_result in self.internal_results:
+            if suite_result.unsuccessful:
+                return True
+        # If all are successful, then this wasn't "unsuccessful"
+        return False
+
 
 #TODO Change from a handler to an internal post processor so it can be used
 # to reprint results