ref: acdc9fd4e91cc45e69bd07c9488bb4b22866129d
dir: /tests/execute/0066-cppelse.c/
#define BAR 0
#ifdef BAR
#ifdef FOO
XXX
#ifdef FOO
XXX
#endif
#else
#define FOO
#ifdef FOO
int x = BAR;
#endif
#endif
#endif
int
main()
{
return BAR;
}