add tests

test/runtime/samples/assignment-to-const1/_config.js

@@ -0,0 +1,3 @@
+export default {
+	html: '<p>2, 1</p>'
+};

test/runtime/samples/assignment-to-const1/main.svelte

@@ -0,0 +1,6 @@
+<script>
+	const arr = [1, 2];
+	[arr[0], arr[1]] = [arr[1], arr[0]];
+</script>
+
+<p>{arr[0]}, {arr[1]}</p>

test/runtime/samples/assignment-to-const2/_config.js

@@ -0,0 +1,3 @@
+export default {
+	html: '<p>[{"a":2},100]</p>'
+};

test/runtime/samples/assignment-to-const2/main.svelte

@@ -0,0 +1,7 @@
+<script>
+	const a = 100;
+	const arr = [{ a: 1 }, 2];
+	[arr[0].a, arr[1] = a] = [arr[1]];
+</script>
+
+<p>{JSON.stringify(arr)}</p>

test/validator/samples/assignment-to-const-8/errors.json

@@ -0,0 +1 @@
+[]

test/validator/samples/assignment-to-const-8/input.svelte

@@ -0,0 +1,6 @@
+<script>
+	const arr = [1, 2];
+	[arr[0], arr[1] = arr] = [arr[1], arr[0]];
+</script>
+
+{arr}