[turbofan] Make sure Operator is really immutable.

test/cctest/compiler/test-js-context-specialization.cc

 // Copyright 2014 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-specialization.h"
 #include "src/compiler/js-operator.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties-inl.h"
 #include "src/compiler/simplified-node-factory.h"
 #include "src/compiler/source-position.h"
@@ skipping 77 matching lines @@
     // Mutable slot, constant context, depth > 0 => fold-in parent context.
     Node* load = t.NewNode(
         t.javascript()->LoadContext(2, Context::GLOBAL_EVAL_FUN_INDEX, false),
         deep_const_context, deep_const_context, start);
     Reduction r = spec.ReduceJSLoadContext(load);
     CHECK(r.Changed());
     Node* new_context_input = NodeProperties::GetValueInput(r.replacement(), 0);
     CHECK_EQ(IrOpcode::kHeapConstant, new_context_input->opcode());
     ValueMatcher<Handle<Context> > match(new_context_input);
     CHECK_EQ(*native, *match.Value());
-    ContextAccess access = static_cast<Operator1<ContextAccess>*>(
-                               r.replacement()->op())->parameter();
+    ContextAccess access = OpParameter<ContextAccess>(r.replacement());
     CHECK_EQ(Context::GLOBAL_EVAL_FUN_INDEX, access.index());
     CHECK_EQ(0, access.depth());
     CHECK_EQ(false, access.immutable());
   }
 
   {
     // Immutable slot, constant context, depth = 0 => specialize.
     Node* load = t.NewNode(t.javascript()->LoadContext(0, slot, true),
                            const_context, const_context, start);
     Reduction r = spec.ReduceJSLoadContext(load);
@@ skipping 59 matching lines @@
     // Mutable slot, constant context, depth > 0 => fold-in parent context.
     Node* load = t.NewNode(
         t.javascript()->StoreContext(2, Context::GLOBAL_EVAL_FUN_INDEX),
         deep_const_context, deep_const_context, start);
     Reduction r = spec.ReduceJSStoreContext(load);
     CHECK(r.Changed());
     Node* new_context_input = NodeProperties::GetValueInput(r.replacement(), 0);
     CHECK_EQ(IrOpcode::kHeapConstant, new_context_input->opcode());
     ValueMatcher<Handle<Context> > match(new_context_input);
     CHECK_EQ(*native, *match.Value());
-    ContextAccess access = static_cast<Operator1<ContextAccess>*>(
-                               r.replacement()->op())->parameter();
+    ContextAccess access = OpParameter<ContextAccess>(r.replacement());
     CHECK_EQ(Context::GLOBAL_EVAL_FUN_INDEX, access.index());
     CHECK_EQ(0, access.depth());
     CHECK_EQ(false, access.immutable());
   }
 }
 
 
 // TODO(titzer): factor out common code with effects checking in typed lowering.
 static void CheckEffectInput(Node* effect, Node* use) {
   CHECK_EQ(effect, NodeProperties::GetEffectInput(use));
@@ skipping 109 matching lines @@
   {
     FunctionTester T(
         "(function() { if (false) { var x = 1; } function inc(a)"
         " { return a + x; } return inc; })()");  // x is undefined!
 
     CHECK(T.Call(T.Val(0.0), T.Val(0.0)).ToHandleChecked()->IsNaN());
     CHECK(T.Call(T.Val(2.0), T.Val(0.0)).ToHandleChecked()->IsNaN());
     CHECK(T.Call(T.Val(-2.1), T.Val(0.0)).ToHandleChecked()->IsNaN());
   }
 }