Handle projection predicates in the param env for auto-trait docs

Fixes #72213

Any predicates in the param env are guaranteed to hold, so we don't need
to do any additional processing of them if we come across them as
sub-obligations of a different predicate. This allows us to avoid adding
the same predicate to the computed ParamEnv multiple times (but with
different regions each time), which causes an ambiguity error during
fulfillment.

0 files changed, 0 insertions, 0 deletions