fix: print `{#await ... catch}` et al correctly (#18645)

needs to check the error value, not the then value

---------

Co-authored-by: Simon H <5968653+dummdidumm@users.noreply.github.com>

.changeset/eighty-pugs-shave.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: correctly print `{#await ... catch x}` et al

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

@@ -763,7 +763,7 @@ const svelte_visitors = (comments, state) => ({
 		}
 
 		if (node.catch) {
-			context.write(node.value ? 'catch ' : 'catch');
+			context.write(node.error ? 'catch ' : 'catch');
 			if (node.error) context.visit(node.error);
 			context.write('}');
 

packages/svelte/tests/print/samples/await-block/input.svelte

@@ -8,3 +8,29 @@
 	<!-- promise was rejected -->
 	<p>Something went wrong: {error.message}</p>
 {/await}
+
+{#await promise catch error}
+	<p>The error is {error}</p>
+{/await}
+
+{#await promise then value}
+	<p>The value is {value}</p>
+{/await}
+
+{#await promise catch}
+	<p>Something went wrong</p>
+{/await}
+
+{#await promise}
+	<p>waiting for the promise to resolve...</p>
+{:then}
+	<p>the promise resolved</p>
+{:catch error}
+	<p>The error is {error}</p>
+{/await}
+
+{#await promise}
+	<p>waiting for the promise to resolve...</p>
+{:catch}
+	<p>Something went wrong</p>
+{/await}

packages/svelte/tests/print/samples/await-block/output.svelte

@@ -8,3 +8,29 @@
 	<!-- promise was rejected -->
 	<p>Something went wrong: {error.message}</p>
 {/await}
+
+{#await promise catch error}
+	<p>The error is {error}</p>
+{/await}
+
+{#await promise then value}
+	<p>The value is {value}</p>
+{/await}
+
+{#await promise catch}
+	<p>Something went wrong</p>
+{/await}
+
+{#await promise}
+	<p>waiting for the promise to resolve...</p>
+{:then}
+	<p>the promise resolved</p>
+{:catch error}
+	<p>The error is {error}</p>
+{/await}
+
+{#await promise}
+	<p>waiting for the promise to resolve...</p>
+{:catch}
+	<p>Something went wrong</p>
+{/await}