This now uses `node_to_string` for both missing and seen Ids, which includes
the snippet of code for which the Id was allocated.
Also removes the duplicated printing of `HirId`, as `node_to_string` includes that already.
Similarly, changes all other users of `node_to_string` that do so, and changes the output of `node_to_string`, which is now "$hirid ($what `$span` in $path)".

…use, r=compiler-errors

Add explanatory message for [#must_use] in ops

Fixes rust-lang#103320

…-field-pat, r=jackh726

Recover `_` as `..` in field pattern

…errors

Improve pretty-printing of `HirIdValidator` errors

This now uses `node_to_string` for both missing and seen Ids, which includes the snippet of code for which the Id was allocated. Also removes the duplicated printing of `HirId`, as `node_to_string` also includes that.

…elper, r=oli-obk

 Replace `ConstFnMutClosure` with const closures

Also fixes a parser bug. cc `@oli-obk` for compiler changes

Rename `rust_2015` → `is_rust_2015`

r? `@compiler-errors`
rust-lang#107508 (comment)

…=jyn514

Reinstate the `hir-stats.rs` tests on stage 1.

r? `@the8472`