Move arena_vec inside lowering.

src/librustc/hir/lowering.rs

@@ -32,9 +32,6 @@
 //! get confused if the spans from leaf AST nodes occur in multiple places
 //! in the HIR, especially for multiple identifiers.
 
-mod expr;
-mod item;
-
 use crate::arena::Arena;
 use crate::dep_graph::DepGraph;
 use crate::hir::def::{DefKind, Namespace, PartialRes, PerNS, Res};
@@ -76,6 +73,18 @@ use syntax_pos::Span;
 
 use rustc_error_codes::*;
 
+macro_rules! arena_vec {
+    () => (
+        &[]
+    );
+    ($this:expr; $($x:expr),*) => (
+        $this.arena.alloc_from_iter(vec![$($x),*])
+    );
+}
+
+mod expr;
+mod item;
+
 const HIR_ID_COUNTER_LOCKED: u32 = 0xFFFFFFFF;
 
 pub struct LoweringContext<'a, 'hir: 'a> {

src/librustc/hir/mod.rs

@@ -50,15 +50,6 @@ macro_rules! hir_vec {
     );
 }
 
-macro_rules! arena_vec {
-    () => (
-        &[]
-    );
-    ($this:expr; $($x:expr),*) => (
-        $this.arena.alloc_from_iter(vec![$($x),*])
-    );
-}
-
 pub mod check_attr;
 pub mod def;
 pub mod def_id;