[lldb] Make TestGuiBasicDebug more lenient

Matt's change to the register allocator in 89baeaef changed where we
end up after the `finish`. Before we'd end up on line 4.

* thread #1, queue = 'com.apple.main-thread', stop reason = step out
Return value: (int) $0 = 1
    frame #0: 0x0000000100003f7d a.out`main(argc=1, argv=0x00007ffeefbff630) at main.c:4:3
   1    extern int func();
   2
   3    int main(int argc, char **argv) {
-> 4      func(); // Break here
   5      func(); // Second
   6      return 0;
   7    }

Now, we end up on line 5.

* thread #1, queue = 'com.apple.main-thread', stop reason = step out
Return value: (int) $0 = 1

    frame #0: 0x0000000100003f8d a.out`main(argc=1, argv=0x00007ffeefbff630) at main.c:5:3
   2
   3    int main(int argc, char **argv) {
   4      func(); // Break here
-> 5      func(); // Second
   6      return 0;
   7    }

Given that this is not expected stable to be stable I've made the test a
bit more lenient to accept both scenarios.