Replace kw_span by full span.

compiler/rustc_ast/src/ast.rs

@@ -385,8 +385,8 @@ pub enum GenericParamKind {
     },
     Const {
         ty: P<Ty>,
-        /// Span of the `const` keyword.
-        kw_span: Span,
+        /// Span of the whole parameter definition, including default.
+        span: Span,
         /// Optional default value for the const generic param.
         default: Option<AnonConst>,
     },
@@ -410,10 +410,7 @@ impl GenericParam {
                 self.ident.span
             }
             GenericParamKind::Type { default: Some(ty) } => self.ident.span.to(ty.span),
-            GenericParamKind::Const { kw_span, default: Some(default), .. } => {
-                kw_span.to(default.value.span)
-            }
-            GenericParamKind::Const { kw_span, default: None, ty } => kw_span.to(ty.span),
+            GenericParamKind::Const { span, .. } => *span,
         }
     }
 }

compiler/rustc_ast/src/visit.rs

@@ -1350,9 +1350,10 @@ macro_rules! common_visitor_and_walkers {
             match kind {
                 GenericParamKind::Lifetime => (),
                 GenericParamKind::Type { default } => visit_opt!(vis, visit_ty, default),
-                GenericParamKind::Const { ty, default, kw_span: _ } => {
+                GenericParamKind::Const { ty, default, span } => {
                     try_visit!(vis.visit_ty(ty));
                     visit_opt!(vis, visit_anon_const, default);
+                    try_visit!(visit_span(vis, span));
                 }
             }
             if let Some(sp) = colon_span {