[turbofan] Minor cleanup to reduce code duplication.

test/unittests/compiler/js-builtin-reducer-unittest.cc

Index: test/unittests/compiler/js-builtin-reducer-unittest.cc
diff --git a/test/unittests/compiler/js-builtin-reducer-unittest.cc b/test/unittests/compiler/js-builtin-reducer-unittest.cc
index 0747f0c876abacbef9285946971d63bfa312e148..87d1ad53b81fdfefdefbc1b3e6789fb0d95ed868 100644
--- a/test/unittests/compiler/js-builtin-reducer-unittest.cc
+++ b/test/unittests/compiler/js-builtin-reducer-unittest.cc
@@ -29,12 +29,6 @@ class JSBuiltinReducerTest : public TypedGraphTest {
     return reducer.Reduce(node);
   }
 
-  Node* Parameter(Type* t, int32_t index = 0) {
-    Node* n = graph()->NewNode(common()->Parameter(index), graph()->start());
-    NodeProperties::SetBounds(n, Bounds(Type::None(), t));
-    return n;
-  }
-
   Handle<JSFunction> MathFunction(const char* name) {
     Handle<Object> m =
         JSObject::GetProperty(isolate()->global_object(),