rust/library/core
bors 792c645ca7 Auto merge of #75145 - davidtwco:issue-60607-preallocate-defid-for-lang-items, r=petrochenkov
Reference lang items during AST lowering

Fixes #60607 and fixes #61019.

This PR introduces `QPath::LangItem` to the HIR and uses it in AST lowering instead of constructing a `hir::Path` from a slice of symbols:

- Credit for much of this work goes to @matthewjasper, I basically just [rebased their earlier work](a227c706b7 (diff-c0f791ead38d2d02916faaad0f56f41d)).
- ~~Changes to Clippy might not be correct, they compile but attempting to run tests through `./x.py` produced failures which appeared spurious, so I didn't run any clippy tests.~~
- Changes to save analysis might not be correct - tests pass but I don't have a lot of confidence in those changes being correct.
- I've used `GenericBounds::LangItemTrait` rather than changing `PolyTraitRef`, as suggested by @matthewjasper [in this comment](a227c706b7 (r40107992)) but I'd prefer that be left for a follow-up.
- I've split things into smaller commits fairly arbitrarily to make the diff easier to review, each commit should compile but might not pass tests until the final commit.

r? @oli-obk
cc @matthewjasper
2020-08-17 20:51:59 +00:00
..
benches
src Auto merge of #75145 - davidtwco:issue-60607-preallocate-defid-for-lang-items, r=petrochenkov 2020-08-17 20:51:59 +00:00
tests Add drop check test & MaybeUninit::first_ptr_mut 2020-08-13 03:51:08 +00:00
Cargo.toml