track reassignments separately from mutations

packages/svelte/src/compiler/phases/scope.js

@@ -638,7 +638,10 @@ export function create_scopes(ast, root, allow_reactive_declarations, parent) {
 		} else {
 			extract_identifiers(node).forEach((identifier) => {
 				const binding = scope.get(identifier.name);
-				if (binding) binding.mutated = true;
+				if (binding) {
+					binding.mutated = true;
+					binding.reassigned = true;
+				}
 			});
 		}
 	}

packages/svelte/src/compiler/types/index.d.ts

@@ -269,6 +269,7 @@ export interface Binding {
 	is_called: boolean;
 	references: { node: Identifier; path: SvelteNode[] }[];
 	mutated: boolean;
+	reassigned: boolean;
 	scope: Scope;
 	/** For `legacy_reactive`: its reactive dependencies */
 	legacy_dependencies: Binding[];