DefPathData::AnonAssocTy
PR #137977 changed `DefPathData::TypeNs` to contain `Option<Symbol>` to account for RPITIT assoc types being anonymous. This commit changes it back to `Symbol` and gives anonymous assoc types their own variant. It makes things a bit nicer overall.
extern "rust-intrinsic"
TypingMode::Borrowck
BitSet
DenseBitSet