Debugger: Handle extra dumpers with LLDB

This generalizes part of the previously GDB-only code paths

Change-Id: Id32798073e3c8bcb23bfedf463bebc866c8275e2
Reviewed-by: hjk <hjk@theqtcompany.com>

src/plugins/debugger/watchhandler.h

@@ -217,6 +217,7 @@ public:
 
     int format(const QByteArray &iname) const;
 
+    void addDumpers(const GdbMi &dumpers);
     void addTypeFormats(const QByteArray &type, const QStringList &formats);
     void setTypeFormats(const DumperTypeFormats &typeFormats);
     DumperTypeFormats typeFormats() const;