util: fix inspect performance bug
In case an object contained a circular reference Object.keys
was
called even though it was not necessary at all. This caused a
significant overhead for objects that contained a lot of such entries.
Checklist
-
make -j4 test
(UNIX), orvcbuild test
(Windows) passes -
tests and/or benchmarks are included -
documentation is changed or added -
commit message follows commit guidelines