Auto merge of #110407 - Nilstrieb:fluent-macro, r=davidtwco

Add `rustc_fluent_macro` to decouple fluent from `rustc_macros`

Fluent, with all the icu4x it brings in, takes quite some time to compile. `fluent_messages!` is only needed in further downstream rustc crates, but is blocking more upstream crates like `rustc_index`. By splitting it out, we allow `rustc_macros` to be compiled earlier, which speeds up `x check compiler` by about 5 seconds (and even more after the needless dependency on `serde_json` is removed from `rustc_data_structures`).

1 files changed, 1 insertions, 1 deletions

diff --git a/compiler/rustc_ast_lowering/src/lib.rs b/compiler/rustc_ast_lowering/src/lib.rs
index 537c2a06183..bfd9956b004 100644
--- a/compiler/rustc_ast_lowering/src/lib.rs
+++ b/compiler/rustc_ast_lowering/src/lib.rs
@@ -55,13 +55,13 @@ use rustc_data_structures::sync::Lrc;
 use rustc_errors::{
     DiagnosticArgFromDisplay, DiagnosticMessage, Handler, StashKey, SubdiagnosticMessage,
 };
+use rustc_fluent_macro::fluent_messages;
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, LifetimeRes, Namespace, PartialRes, PerNS, Res};
 use rustc_hir::def_id::{LocalDefId, CRATE_DEF_ID};
 use rustc_hir::definitions::DefPathData;
 use rustc_hir::{ConstArg, GenericArg, ItemLocalId, ParamName, TraitCandidate};
 use rustc_index::vec::{Idx, IndexSlice, IndexVec};
-use rustc_macros::fluent_messages;
 use rustc_middle::{
     span_bug,
     ty::{ResolverAstLowering, TyCtxt},