Now that the checks no longer run from `mach build`, mozlint is their only consumer, so keep them next to the linter that drives them instead of in config/. check_js_opcode.py derived topsrcdir from its own depth in the tree, so bump it to match the new location. Since /config/** was packaged wholesale into the standalone SpiderMonkey source tarball but /tools/ is cherry-picked, add an explicit filter so the checks stay available there. Differential Revision: https://phabricator.services.mozilla.com/D323630