Allows that the error message is absent in "uncaught exceptions".
This ensures throw new Test262Error() in test262 is correctly handled.
For example all tests in https://test262.report/browse/annexB/language/comments are currently marked as failing in SpiderMonkey, even though SpiderMonkey actually passes these tests. It's just that eshost doesn't correctly parse the error string reported from SpiderMonkey.
505e5c4:
Improves the error parser to include stack frames.
11bf59d:
9b99cc6:
throw new Test262Error()
in test262 is correctly handled.eshost
doesn't correctly parse the error string reported from SpiderMonkey.505e5c4: