convert inherent-impl-related things to on-demand queries

There are now 3 queries:

- inherent_impls(def-id): for a given type, get a `Rc<Vec<DefId>>` with
  all its inherent impls. This internally uses `crate_inherent_impls`,
  doing some hacks to keep the current deps (which, btw, are not clearly
  correct).
- crate_inherent_impls(crate): gathers up a map from types
  to `Rc<Vec<DefId>>`, touching the entire krate, possibly generating
  errors.
- crate_inherent_impls_overlap_check(crate): performs overlap checks
  between the inherent impls for a given type, generating errors.

0 files changed, 0 insertions, 0 deletions