Correcting extending nodes for Math.TruncNode.

Author: ppisl

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/MathModuleBuiltins.java

@@ -42,6 +42,7 @@
 import com.oracle.graal.python.builtins.objects.tuple.PTuple;
 import com.oracle.graal.python.nodes.call.special.LookupAndCallUnaryNode;
 import com.oracle.graal.python.nodes.function.PythonBuiltinNode;
+import com.oracle.graal.python.nodes.function.builtins.PythonUnaryBuiltinNode;
 import com.oracle.graal.python.nodes.truffle.PythonArithmeticTypes;
 import com.oracle.graal.python.runtime.exception.PythonErrorType;
 import com.oracle.graal.python.runtime.object.PythonObjectFactory;
@@ -958,7 +959,7 @@ public abstract static class PowNode extends PythonBuiltinNode {
 
     @Builtin(name = "trunc", fixedNumOfArguments = 1)
     @GenerateNodeFactory
-    public abstract static class TruncNode extends PythonBuiltinNode {
+    public abstract static class TruncNode extends PythonUnaryBuiltinNode {
 
         @Specialization
         Object trunc(Object obj,