Test coverage

Hello, folks. If this is not the place to ask, I'm sorry.

I would like to know how or where I can find the code coverage for
php-src to see if there is any uncovered code I might be able to
contribute with new tests.

Since gcov.php.net doesn't exist anymore, I was not able to find
anything related to it anywhere. I even tried generating a coverage
report locally with `lcov --capture --directory . --output-file
coverage.info` after running `make test`, but I got no luck with it.

Thank you in advance for your help.