Cannot deal inline frames in gdb

HI, I have found another bug while unstack gdb call stacks, with this input:

```
#5  0x00007f2a68255269 in Lock (Section=..., this=<synthetic pointer>) at /var/lib/Section.h:49
#6  Job::Pausing (this=0x9f1cfbe0) at /var/libJob.cpp:3661
#7  0x00007f2a6e15dfc7 in Task::Run() () at /var/lib/nTask.cpp:218
```

Frame 6 will be omitted in the result.