lisa.doc.helpers: Make is_test() more robust
lisa.doc.helpers: Make is_test() more robust

inspect.signature() resolves the annotations if they are type names instead of
being types. Accessing the return annotation through it is therefore more robust
than using x.__annotations__['return'].

ARM-software/lisa,ARM-software/lisa,credp/lisa,credp/lisa,ARM-software/lisa,credp/lisa,ARM-software/lisa,credp/lisa