It's not even stable in rustc so it shouldn't be stable in rustdoc.

In order that we can successfully later resolve paths in crates
which weren't loaded as a result of merely parsing the crate
we're documenting, we force the resolution of the path to each
crate before cloning the resolver to use later.  Closes #66159
Signed-off-by: NDaniel Silverstone <dsilvers@digital-scurf.org>