Add test case for computed bind

test/runtime/samples/binding-this-component-computed-key/Foo.svelte

@@ -0,0 +1 @@
+<div>foo</div>

test/runtime/samples/binding-this-component-computed-key/_config.js

@@ -0,0 +1,8 @@
+export default {
+	skip_if_ssr: true,
+
+	html: `
+		<div>foo</div>
+		<div>has foo: true</div>
+	`
+};

test/runtime/samples/binding-this-component-computed-key/main.svelte

@@ -0,0 +1,9 @@
+<script>
+	import Foo from './Foo.svelte';
+	export let foo = {};
+</script>
+
+<Foo bind:this={foo['computed']}/>
+<div>
+	has foo: {!!foo.computed}
+</div>