Bug
1837620 - Part 7: Keep JitScripts in a linked list to avoid iterating all BaseScripts r=jandem
Currently we iterate all BaseScripts to find the JitScripts in a zone. This is
inefficient since there can be many times more BaseScripts that JitScripts
(e.g. 10 - 20 times more).
Instead, keep all JitScripts in a zone in a linked list and use that to iterate
through them. This required giving JitScript a pointer to its owning JSScript
since that was needed in a few cases.
Differential Revision: https://phabricator.services.mozilla.com/
D182219