macros: hygienize use of `core`/`std` in builtin macros#46550

Merged

bors merged 4 commits intorust-lang:masterfrom

jseyfried:cleanup_builtin_hygiene

Dec 13, 2017

Commits on Dec 10, 2017

Use hygiene to access the injected crate (`core` or `std`) from builtin macros.
jseyfried
committed

Commits on Dec 12, 2017

Commits on Dec 13, 2017

Improve pretty printing `$crate::` paths.
jseyfried
committed