src/vs/workbench/services/extensions/electron-browser/cachedExtensionScanner.ts/getSystemExtensionsRoot
function getSystemExtensionsRoot(): string {
	if (!_SystemExtensionsRoot) {
		_SystemExtensionsRoot = path.normalize(path.join(FileAccess.asFileUri('', require).fsPath, '..', 'extensions'));
	}
	return _SystemExtensionsRoot;
}