[lldb] Make TestGuiBasicDebug more lenient

Matt's change to the register allocator in 89baeaef2fa9 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.