src/vs/base/node/shell.ts/getSystemShellSync
export function getSystemShellSync(os: platform.OperatingSystem, env: platform.IProcessEnvironment): string {
	if (os === platform.OperatingSystem.Windows) {
		if (platform.isWindows) {
			return getSystemShellWindowsSync(env);
		}
		// Don't detect Windows shell when not on Windows
		return processes.getWindowsShell(env);
	}

	return getSystemShellUnixLike(os, env);
}