Fix gdb.FinishBreakpoint when returning to an inlined function

Currently, when creating a gdb.FinishBreakpoint in a function
called from an inline frame, it will never be hit:
```
(gdb) py fb=gdb.FinishBreakpoint()
Temporary breakpoint 1 at 0x13f1917b4: file C:/src/repos/binutils-gdb.git/gdb/testsuite/gdb.python/py-finish-breakpoint.c, line 47.
(gdb) c
Continuing.
Thread-specific breakpoint 1 deleted - thread 1 no longer in the thread list.
[Inferior 1 (process 1208) exited normally]
```

The reason is that the frame_id of a breakpoint has to be the
ID of a real frame, ignoring any inline frames.

With this fixed, it's working correctly:
```
(gdb) py fb=gdb.FinishBreakpoint()
Temporary breakpoint 1 at 0x13f5617b4: file C:/src/repos/binutils-gdb.git/gdb/testsuite/gdb.python/py-finish-breakpoint.c, line 47.
(gdb) c
Continuing.

Breakpoint 1, increase_inlined (a=0x40fa5c) at C:/src/repos/binutils-gdb.git/gdb/testsuite/gdb.python/py-finish-breakpoint.c:47
(gdb) py print(fb.return_value)
-8
```

Approved-By: Tom Tromey <tom@tromey.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/gdb/python/py-finishbreakpoint.c b/gdb/python/py-finishbreakpoint.c
index 627eb29..7f3658d 100644
--- a/gdb/python/py-finishbreakpoint.c
+++ b/gdb/python/py-finishbreakpoint.c
@@ -212,7 +212,8 @@ bpfinishpy_init (PyObject *self, PyObject *args, PyObject *kwargs)
 				 "be set on a dummy frame."));
 	    }
 	  else
-	    frame_id = get_frame_id (prev_frame);
+	    /* Get the real calling frame ID, ignoring inline frames.  */
+	    frame_id = frame_unwind_caller_id (frame);
 	}
     }
   catch (const gdb_exception &except)