TurboTax certainly does allow you to report stock sales where no 1099-B is issued.
The very first question asked when you start the "Stocks, Mutual Funds, Bonds, Other" interview is "Did you get a 1099-B or brokerage statement for these sales?"
If you answer "Yes" you're launched into an interview that expressly references the 1099-B.
If you answer "No" you're launched into a slightly different interview with the first question being "Choose the type of investment you sold". Among the investment types available is "Employee Stock Purchase Plan".
Tom Young