gobject_gdb.py: adapt to recent gsignal changes

Add to script the new functions added in
commit 2368187e and commit e5ee6e14 which are:

signal_emitv_unlocked()
signal_emit_valist_unlocked()

so that the "<emit signal 'blabla'>" line keeps
showing after them.

gobject/gobject_gdb.py

@@ -318,6 +318,8 @@ class GFrameDecorator:
                     "g_signal_emit_valist",
                     "g_signal_emit",
                     "g_signal_emit_by_name",
+                    "signal_emitv_unlocked",
+                    "signal_emit_valist_unlocked",
                 ]:
                     end = end + 1
                 else: