Improve perf when ignore illegal is off

Most users will have it on, but this improves perf a bit when it isn't.

Just skips a check, which improves perf a good bit.  But overall it's still a pretty huge hit - 17% slower with ignore off.  It does verify the coreState on every read that doesn't pass the safe check, though.  Maybe I need to allow uncached reads to pass or something...

-[Unknown]