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

1 files changed, 2 insertions, 2 deletions

diff --git a/compiler/rustc_const_eval/src/interpret/place.rs b/compiler/rustc_const_eval/src/interpret/place.rs
index ff6db143ddf..a95bcaa3f99 100644
--- a/compiler/rustc_const_eval/src/interpret/place.rs
+++ b/compiler/rustc_const_eval/src/interpret/place.rs
@@ -8,7 +8,7 @@ use rustc_ast::Mutability;
 use rustc_middle::mir;
 use rustc_middle::ty;
 use rustc_middle::ty::layout::{LayoutOf, TyAndLayout};
-use rustc_target::abi::{self, Abi, Align, HasDataLayout, Size, VariantIdx};
+use rustc_target::abi::{self, Abi, Align, HasDataLayout, Size, FIRST_VARIANT};
 
 use super::{
     alloc_range, mir_assign_valid_types, AllocId, AllocRef, AllocRefMut, CheckInAllocMsg,
@@ -796,7 +796,7 @@ where
                 let variant_dest = self.place_downcast(&dest, variant_index)?;
                 (variant_index, variant_dest, active_field_index)
             }
-            _ => (VariantIdx::from_u32(0), dest.clone(), None),
+            _ => (FIRST_VARIANT, dest.clone(), None),
         };
         if active_field_index.is_some() {
             assert_eq!(operands.len(), 1);