Inputs occured in depGraph cycle is dangenrous and should be treated as an
invariant since Forget _may_ generate broken code in this case, despite that
technically this is a stricter then what we needed for the particular case of
#633 and #634 and there could be case that this is safe (like many `cfg-`
tests that I have to mark as `bailout.`)
I expect the next diff will fix them though.
commit-id:0b13ed02