Auto merge of #109626 - matthiaskrgr:rollup-k0y7bdd, r=matthiaskrgr

Rollup of 6 pull requests

Successful merges:

 - #109007 (rustdoc: skip `// some variants omitted` if enum is `#[non_exhaustive]`)
 - #109593 (Rustdoc Book refer to rustdoc::missing_doc_code_examples. Fixes #109592.)
 - #109595 (Improve "Auto-hide trait implementation documentation" GUI test)
 - #109619 (Still-further-specializable projections are ambiguous in new solver)
 - #109620 (Correct typo (`back_box` -> `black_box`))
 - #109621 (Refactor: `VariantIdx::from_u32(0)` -> `FIRST_VARIANT`)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

3 files changed, 3 insertions, 3 deletions

diff --git a/compiler/rustc_codegen_cranelift/src/base.rs b/compiler/rustc_codegen_cranelift/src/base.rs
index 2107ae147e9..1825fb8cb22 100644
--- a/compiler/rustc_codegen_cranelift/src/base.rs
+++ b/compiler/rustc_codegen_cranelift/src/base.rs
@@ -785,7 +785,7 @@ fn codegen_stmt<'tcx>(
                             let variant_dest = lval.downcast_variant(fx, variant_index);
                             (variant_index, variant_dest, active_field_index)
                         }
-                        _ => (VariantIdx::from_u32(0), lval, None),
+                        _ => (FIRST_VARIANT, lval, None),
                     };
                     if active_field_index.is_some() {
                         assert_eq!(operands.len(), 1);
diff --git a/compiler/rustc_codegen_cranelift/src/lib.rs b/compiler/rustc_codegen_cranelift/src/lib.rs
index bed79859f51..1bd03403f24 100644
--- a/compiler/rustc_codegen_cranelift/src/lib.rs
+++ b/compiler/rustc_codegen_cranelift/src/lib.rs
@@ -86,7 +86,7 @@ mod prelude {
         self, FloatTy, Instance, InstanceDef, IntTy, ParamEnv, Ty, TyCtxt, TypeAndMut,
         TypeFoldable, TypeVisitableExt, UintTy,
     };
-    pub(crate) use rustc_target::abi::{Abi, Scalar, Size, VariantIdx};
+    pub(crate) use rustc_target::abi::{Abi, Scalar, Size, VariantIdx, FIRST_VARIANT};
 
     pub(crate) use rustc_data_structures::fx::FxHashMap;
 
diff --git a/compiler/rustc_codegen_cranelift/src/unsize.rs b/compiler/rustc_codegen_cranelift/src/unsize.rs
index ecf187a0b0f..93eefd92342 100644
--- a/compiler/rustc_codegen_cranelift/src/unsize.rs
+++ b/compiler/rustc_codegen_cranelift/src/unsize.rs
@@ -146,7 +146,7 @@ pub(crate) fn coerce_unsized_into<'tcx>(
         (&ty::Adt(def_a, _), &ty::Adt(def_b, _)) => {
             assert_eq!(def_a, def_b);
 
-            for i in 0..def_a.variant(VariantIdx::new(0)).fields.len() {
+            for i in 0..def_a.variant(FIRST_VARIANT).fields.len() {
                 let src_f = src.value_field(fx, mir::Field::new(i));
                 let dst_f = dst.place_field(fx, mir::Field::new(i));