Program ebpf_samples/build/twotypes explicitly requires keeping track of two ptr types for a register

[a-hamza-r]

The program twotypes requires keeping track of two ptr types, shared and stack for a register. The analysis has been implemented in latest PREVAIL, but not in type domain, as it keeps track of only one type, not more. The significant code snippet is:

uint8_t* ptr;
if (rand32 & 1) {
    ptr = map_value;
} else {
    ptr = stack_buffer + 128;
}