fix: allow whitespace before an after snippet parameters

fixes #12156

Author: dummdidumm

packages/svelte/src/compiler/phases/1-parse/state/tag.js

@@ -269,6 +269,8 @@ function open(parser) {
 			e.expected_identifier(parser.index);
 		}
 
+		parser.allow_whitespace();
+
 		const params_start = parser.index;
 
 		parser.eat('(', true);
@@ -289,6 +291,7 @@ function open(parser) {
 			parse_expression_at(prelude + `${params} => {}`, parser.ts, params_start)
 		);
 
+		parser.allow_whitespace();
 		parser.eat('}', true);
 
 		/** @type {ReturnType<typeof parser.append<import('#compiler').SnippetBlock>>} */

packages/svelte/tests/validator/samples/snippet-whitespace-ok/errors.json

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

packages/svelte/tests/validator/samples/snippet-whitespace-ok/input.svelte

@@ -0,0 +1,4 @@
+<!-- prettier-ignore -->
+{#snippet ok () }
+	asd
+{/snippet}