fix microsoft#210999 (microsoft#211326)

Author: sandy081

src/vs/workbench/services/language/common/languageService.ts

@@ -178,10 +178,11 @@ class LanguageTableRenderer extends Disposable implements IExtensionFeatureTable
 			localize('grammar', "Grammar"),
 			localize('snippets', "Snippets")
 		];
-		const rows: IRowData[][] = languages.sort((a, b) => a.id.localeCompare(b.id))
+		const rows: IRowData[][] = languages.sort((a, b) => (a.id || '').localeCompare(b.id || ''))
 			.map(l => {
 				return [
-					l.id, l.name,
+					l.id,
+					l.name,
 					new MarkdownString().appendMarkdown(`${l.extensions.map(e => `\`${e}\``).join(' ')}`),
 					l.hasGrammar ? '✔︎' : '\u2014',
 					l.hasSnippets ? '✔︎' : '\u2014'