test_runner: enable in-source testing
Just opening a draft PR to ask for feedback plus seek some help, have been trying implement in-source testing as per the linked issue, and would like to know if
a) This is the correct way to make the change
b) Also it seems that --test option value is not getting recognized somehow when using it within lib/internal/modules/esm/initialize_import_meta.js which is quite weird if anyone can explain this would be very helpful!!
Also most importantly would need discussion on whether this feature even is acceptable, the discussion on the original issue stopped some time back so hoping this one can continue the conversation