remove useless validation

src/compiler/parse/state/tag.ts

@@ -189,10 +189,6 @@ export default function tag(parser: Parser) {
 		}
 
 		const definition = element.attributes.splice(index, 1)[0];
-		if (definition.value === true	|| !['Text', 'MustacheTag', 'AttributeShorthand'].includes(definition.value[0].type)) {
-			parser.error(parser_errors.invalid_element_definition, definition.start);
-		}
-
 		element.tag = definition.value[0].data || definition.value[0].expression;
 	}