fix handle marking global variable as dependency

src/compiler/compile/nodes/Binding.ts

@@ -52,7 +52,9 @@ export default class Binding extends Node {
 		} else if (this.is_contextual) {
 			scope.dependencies_for_name.get(name).forEach(name => {
 				const variable = component.var_lookup.get(name);
+				if (variable) {
 					variable[this.expression.node.type === 'MemberExpression' ? 'mutated' : 'reassigned'] = true;
+				}
 			});
 		} else {
 			const variable = component.var_lookup.get(name);

test/runtime/samples/bindings-global-dependency/_config.js

@@ -0,0 +1,3 @@
+export default {
+	html: '<input type="text">'
+};

test/runtime/samples/bindings-global-dependency/main.svelte

@@ -0,0 +1,9 @@
+<script>
+	let data = {
+		a: {value:''}
+	}
+</script>
+
+{#each Object.values(data) as object}
+	<input type="text" bind:value={object.value} />
+{/each}