tools: include exit code in test failures

Include the exit code in test failures. This will give us more information during the currently-puzzling failures that provide no information in CI such as: ``` 03:10:10 not ok 563 parallel/test-fs-truncate 03:10:10 --- 03:10:10 duration_ms: 1.119 03:10:10 severity: fail 03:10:10 stack: |- 03:10:10 ... ``` PR-URL: #19855 Reviewed-By: Sakthipriyan Vairamani <[email protected]> Reviewed-By: Ben Noordhuis <[email protected]> Reviewed-By: Gibson Fahnestock <[email protected]> Reviewed-By: Rod Vagg <[email protected]>

Author: Trott

tools/test.py

@@ -285,7 +285,7 @@ def HasRun(self, output):
 ifoutput.UnexpectedOutput():
 status_line='not ok %i %s'% (self._done, command)
 self.severity='fail'
-self.traceback=output.output.stdout+output.output.stderr
+self.traceback="exit code: "+output.output.exit_code+"\n"+output.output.stdout+output.output.stderr
 
 ifFLAKYinoutput.test.outcomesandself.flaky_tests_mode==DONTCARE:
 status_line=status_line+' # TODO : Fix flaky test'