[svn r292] Fixed: string switch was broken in several ways. Fixed: TypeInfo_Typedef.next was incorrect (return base of base instead of just base). Fixed: ClassInfo offset type info (offTi) had invalid offsets.

module bug80;
extern(C) int printf(char*, ...);

void main()
{
    byte b = 10;
    int i = b += 2;
    printf("byte=%d int=%d\n", b, i);
    assert(b == 12);
    assert(i == 12);
}