Debugger: Add a convenience function GdbMi::toInt()

Saves some line noise on the user side.

Change-Id: I9c6d7542195fc7485ac4ee466cd42a28be95b8da
Reviewed-by: David Schulz <david.schulz@digia.com>

src/plugins/debugger/debuggerprotocol.h

@@ -123,6 +123,7 @@ public:
 
     QByteArray toString(bool multiline = false, int indent = 0) const;
     qulonglong toAddress() const;
+    int toInt() const { return m_data.toInt(); }
     void fromString(const QByteArray &str);
     void fromStringMultiple(const QByteArray &str);