Fold PatKind::NamedConstant into PatKind::Constant

compiler/rustc_middle/src/thir.rs

@@ -640,7 +640,6 @@ impl<'tcx> Pat<'tcx> {
             | Range(..)
             | Binding { subpattern: None, .. }
             | Constant { .. }
-            | NamedConstant { .. }
             | Error(_) => {}
             AscribeUserType { subpattern, .. }
             | Binding { subpattern: Some(subpattern), .. }
@@ -787,12 +786,8 @@ pub enum PatKind<'tcx> {
     /// * `String`, if `string_deref_patterns` is enabled.
     Constant {
         value: mir::Const<'tcx>,
-    },
-
-    /// Same as `Constant`, but that came from a `const` that we can point at in diagnostics.
-    NamedConstant {
-        value: mir::Const<'tcx>,
-        span: Span,
+        /// The `const` item this constant came from, if any.
+        opt_def: Option<DefId>,
     },
 
     /// Inline constant found while lowering a pattern.

compiler/rustc_middle/src/thir/visit.rs

@@ -246,7 +246,7 @@ pub fn walk_pat<'thir, 'tcx: 'thir, V: Visitor<'thir, 'tcx>>(
                 visitor.visit_pat(&subpattern.pattern);
             }
         }
-        Constant { value: _ } | NamedConstant { value: _, span: _ } => {}
+        Constant { value: _, opt_def: _ } => {}
         InlineConstant { def: _, subpattern } => visitor.visit_pat(subpattern),
         Range(_) => {}
         Slice { prefix, slice, suffix } | Array { prefix, slice, suffix } => {