[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 scope3;
extern(C) int printf(char*, ...);
void main()
{
    int i;
    while (i < 10) {
        scope(success) i++;
    }
    printf("%d\n", i);
}