Version Used: 4.2.0-1.22104.1 (8d81aa5)

Steps to Reproduce:

public void Method<TEnum>(TEnum command)
    where TEnum : enum
{
}

Expected Behavior:

1. A specific error message is reported on the enum token
2. The compiler recovers from the error with a reasonable parse tree

Actual Behavior:

1. CS1031 (Type expected) is reported
2. Many subsequent parse errors are reported