The calls used old bugzilla URLs and nobody cared about that.
So apparently they are very unused.
There's also a potential conflict between gitlab and bugzilla URLs and
what base bug to use there.
The old usages have been converted to comments.
The speed-up in 7da1f8a1ce was wrong in
certain conditions, even though it didn't trigger the existing
testsuite.
New testcase /bitmask/invert_range_hardcoded included.