Auto merge of #95798 - Dylan-DPC:rollup-51hx1wl, r=Dylan-DPC

Rollup of 7 pull requests

Successful merges:

 - #95102 (Add known-bug for #95034)
 - #95579 (Add `<[[T; N]]>::flatten{_mut}`)
 - #95634 (Mailmap update)
 - #95705 (Promote x86_64-unknown-none target to Tier 2 and distribute build artifacts)
 - #95761 (Kickstart the inner usage of `macro_metavar_expr`)
 - #95782 (Windows: Increase a pipe's buffer capacity to 64kb)
 - #95791 (hide an #[allow] directive from the Arc::new_cyclic doc example)

Failed merges:

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

2 files changed, 3 insertions, 4 deletions

diff --git a/compiler/rustc_expand/src/expand.rs b/compiler/rustc_expand/src/expand.rs
index c3f7f4f27e5..9b224a73356 100644
--- a/compiler/rustc_expand/src/expand.rs
+++ b/compiler/rustc_expand/src/expand.rs
@@ -83,9 +83,7 @@ macro_rules! ast_fragments {
                 }
                 match self {
                     $($(AstFragment::$Kind(ast) => ast.extend(placeholders.iter().flat_map(|id| {
-                        // We are repeating through arguments with `many`, to do that we have to
-                        // mention some macro variable from those arguments even if it's not used.
-                        macro _repeating($flat_map_ast_elt) {}
+                        ${ignore(flat_map_ast_elt)}
                         placeholder(AstFragmentKind::$Kind, *id, None).$make_ast()
                     })),)?)*
                     _ => panic!("unexpected AST fragment kind")
diff --git a/compiler/rustc_expand/src/lib.rs b/compiler/rustc_expand/src/lib.rs
index cd5bb93de65..21078f79f63 100644
--- a/compiler/rustc_expand/src/lib.rs
+++ b/compiler/rustc_expand/src/lib.rs
@@ -1,3 +1,4 @@
+#![allow(rustc::potential_query_instability)]
 #![feature(associated_type_bounds)]
 #![feature(associated_type_defaults)]
 #![feature(crate_visibility_modifier)]
@@ -5,12 +6,12 @@
 #![feature(if_let_guard)]
 #![feature(let_chains)]
 #![feature(let_else)]
+#![feature(macro_metavar_expr)]
 #![feature(proc_macro_diagnostic)]
 #![feature(proc_macro_internals)]
 #![feature(proc_macro_span)]
 #![feature(try_blocks)]
 #![recursion_limit = "256"]
-#![allow(rustc::potential_query_instability)]
 
 #[macro_use]
 extern crate rustc_macros;