[turbofan] Call FastNewContextStub for function context.

test/unittests/compiler/js-context-relaxation-unittest.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/js-context-relaxation.h"
 #include "src/compiler/js-graph.h"
 #include "test/unittests/compiler/graph-unittest.h"
 #include "test/unittests/compiler/node-test-utils.h"
 
 namespace v8 {
@@ skipping 256 matching lines @@
   EXPECT_EQ(nested_context, NodeProperties::GetContextInput(node));
 }
 
 
 TEST_F(JSContextRelaxationTest,
        RelaxJSCallFunctionDeepContextChainPartialNoRelax) {
   Node* const input0 = Parameter(0);
   Node* const input1 = Parameter(1);
   Node* const context = Parameter(2);
   Node* const outer_context = Parameter(3);
-  const Operator* op = javascript()->CreateFunctionContext();
+  const Operator* op = javascript()->CreateFunctionContext(0);
   Node* const effect = graph()->start();
   Node* const control = graph()->start();
   Node* nested_context =
       graph()->NewNode(op, graph()->start(), outer_context, effect, control);
   Node* const frame_state_2 =
       ShallowFrameStateChain(nested_context, CALL_MAINTAINS_NATIVE_CONTEXT);
   Node* node =
       graph()->NewNode(javascript()->CallFunction(2, NO_CALL_FUNCTION_FLAGS,
                                                   STRICT, VectorSlotPair()),
                        input0, input1, context, frame_state_2, effect, control);
   Reduction const r = Reduce(node);
   EXPECT_FALSE(r.Changed());
   EXPECT_EQ(context, NodeProperties::GetContextInput(node));
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8