Align behavior with CRuby for security specs #6304
Description
In #6303 @eregon noticed a few of the security specs do not pass currently.
Tags are here: 48c5e85
An example run is here: https://travis-ci.org/github/jruby/jruby/jobs/702869188
The failures are mostly due to us not randomizing hash calculation, but there's a few others that warrant a second look. I believe it would be best for us to patch these for the 9.2.12 release this week.