trace: Add helper function to cast event arguments

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Message-id: 145641860680.30295.1873612736245870753.stgit@localhost
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

scripts/tracetool/__init__.py

@@ -121,6 +121,10 @@ def types(self):
         """List of argument types."""
         return [ type_ for type_, _ in self._args ]
 
+    def casted(self):
+        """List of argument names casted to their type."""
+        return ["(%s)%s" % (type_, name) for type_, name in self._args]
+
     def transform(self, *trans):
         """Return a new Arguments instance with transformed types.