convert `break $;` to `return;`

packages/svelte/src/compiler/migrate/index.js

@@ -305,11 +305,22 @@ const instance_script = {
 			state.str.update(start, end, '');
 		}
 	},
-	LabeledStatement(node, { path, state }) {
+	BreakStatement(node, { state, path }) {
+		if (path[1].type !== 'LabeledStatement') return;
+		if (node.label?.name !== '$') return;
+		state.str.update(
+			/** @type {number} */ (node.start),
+			/** @type {number} */ (node.end),
+			'return;'
+		);
+	},
+	LabeledStatement(node, { path, state, next }) {
 		if (state.analysis.runes) return;
 		if (path.length > 1) return;
 		if (node.label.name !== '$') return;
 
+		next();
+
 		if (
 			node.body.type === 'ExpressionStatement' &&
 			node.body.expression.type === 'AssignmentExpression'

packages/svelte/tests/migrate/samples/effects/input.svelte

@@ -6,6 +6,8 @@
 	}
 	$: {
 		console.log('foo');
+		if (x) break $;
+		console.log('bar');
 	}
 	$: $count = 1;
 </script>

packages/svelte/tests/migrate/samples/effects/output.svelte

@@ -12,6 +12,8 @@
 	});
 	run(() => {
 		console.log('foo');
+		if (x) return;
+		console.log('bar');
 	});
 	run(() => {
 		$count = 1;