[svn r378] Make some errors fatal to prevent segfaults. Error instead of assert on missing label. Fixes: nocompile/ finally_02, 03, 07, 08 goto_16_A, 16_B, 12, 13, 14

module structs5;

void main()
{
    {S s = S();}
    {T t = T(1);}
    {U u = U();}
}

struct S
{
}

struct T
{
    int i;
}

struct U
{
    S s;
    long l;
}