Remove span from hir::Arm.

Author: cjgillot

src/librustc_ast_lowering/expr.rs

@@ -482,7 +482,6 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 _ => None,
             },
             body: self.lower_expr(&arm.body),
-            span: arm.span,
         }
     }
 
@@ -1807,13 +1806,6 @@ impl<'hir> LoweringContext<'_, 'hir> {
     }
 
     fn arm(&mut self, pat: &'hir hir::Pat<'hir>, expr: &'hir hir::Expr<'hir>) -> hir::Arm<'hir> {
-        hir::Arm {
-            hir_id: self.next_id(expr.span),
-            attrs: &[],
-            pat,
-            guard: None,
-            span: expr.span,
-            body: expr,
-        }
+        hir::Arm { hir_id: self.next_id(expr.span), attrs: &[], pat, guard: None, body: expr }
     }
 }

src/librustc_hir/hir.rs

@@ -1142,7 +1142,6 @@ pub struct Local<'hir> {
 pub struct Arm<'hir> {
     #[stable_hasher(ignore)]
     pub hir_id: HirId,
-    pub span: Span,
     pub attrs: &'hir [Attribute],
     /// If this pattern and the optional guard matches, then `body` is evaluated.
     pub pat: &'hir Pat<'hir>,

src/librustc_middle/hir/map/collector.rs

@@ -416,7 +416,7 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
     fn visit_arm(&mut self, arm: &'hir Arm<'hir>) {
         let node = Node::Arm(arm);
 
-        self.insert(arm.span, arm.hir_id, node);
+        self.insert(DUMMY_SP, arm.hir_id, node);
 
         self.with_parent(arm.hir_id, |this| {
             intravisit::walk_arm(this, arm);

src/librustc_mir_build/hair/cx/expr.rs

@@ -766,7 +766,7 @@ fn convert_arm<'tcx>(cx: &mut Cx<'_, 'tcx>, arm: &'tcx hir::Arm<'tcx>) -> Arm<'t
         body: arm.body.to_ref(),
         lint_level: LintLevel::Explicit(arm.hir_id),
         scope: region::Scope { id: arm.hir_id.local_id, data: region::ScopeData::Node },
-        span: arm.span,
+        span: cx.tcx.hir().span(arm.hir_id),
     }
 }