src/vs/base/node/shell.ts/getSystemShellWindowsSync
function getSystemShellWindowsSync(env: platform.IProcessEnvironment): string {
	if (_TERMINAL_DEFAULT_SHELL_WINDOWS) {
		return _TERMINAL_DEFAULT_SHELL_WINDOWS;
	}

	const isAtLeastWindows10 = platform.isWindows && parseFloat(release()) >= 10;
	const is32ProcessOn64Windows = env.hasOwnProperty('PROCESSOR_ARCHITEW6432');
	const powerShellPath = `${env['windir']}\\${is32ProcessOn64Windows ? 'Sysnative' : 'System32'}\\WindowsPowerShell\\v1.0\\powershell.exe`;
	return isAtLeastWindows10 ? powerShellPath : processes.getWindowsShell(env);
}