Before this fix we applied padding before manually doing what
`convert_benchmarks_to_tests()` does. Instead use
`convert_benchmarks_to_tests()` if applicable and then apply padding
afterwards so it becomes correct. (Benches should only be padded when
run as benches to make it easy to compare the benchmark numbers.)
As you can see the padding is wrong when running benches as tests. This
will be fixed in the next commit. (Benches should only be padded when
run as benches to make it easy to compare the benchmark numbers.)