Fix issue where test page does not run in IE

test/dev-setup.js

@@ -152,7 +152,7 @@
 	self.getCodiconPath = function(PATH_PREFIX) {
 		PATH_PREFIX = PATH_PREFIX || '';
 		const result = RESOLVED_CORE.getResolvedPath(PATH_PREFIX);
-		return `${result}/base/browser/ui/codiconLabel/codicon/codicon.ttf`;
+		return result + '/base/browser/ui/codiconLabel/codicon/codicon.ttf';
 	};