[turbofan] Allow deoptimization for JSToNumber operator.

src/compiler/js-graph.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/code-stubs.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/node-properties-inl.h"
 #include "src/compiler/typer.h"
 
 namespace v8 {
@@ skipping 173 matching lines @@
 
 Node* JSGraph::Float64Constant(double value) {
   Node** loc = cache_.FindFloat64Constant(value);
   if (*loc == NULL) {
     *loc = graph()->NewNode(common()->Float64Constant(value));
   }
   return *loc;
 }
 
 
+Node* JSGraph::EmptyFrameState() {
+  if (!empty_frame_state_.is_set()) {
+    Node* values = graph()->NewNode(common()->StateValues(0));
+    Node* state_node = graph()->NewNode(
+        common()->FrameState(JS_FRAME, BailoutId(0),
+                             OutputFrameStateCombine::Ignore()),
+        values, values, values, NoContextConstant(), UndefinedConstant());
+    empty_frame_state_.set(state_node);
+  }
+  return empty_frame_state_.get();
+}
+
+
 Node* JSGraph::ExternalConstant(ExternalReference reference) {
   Node** loc = cache_.FindExternalConstant(reference);
   if (*loc == NULL) {
     *loc = graph()->NewNode(common()->ExternalConstant(reference));
   }
   return *loc;
 }
 
 
 void JSGraph::GetCachedNodes(NodeVector* nodes) {
   cache_.GetCachedNodes(nodes);
   SetOncePointer<Node>* ptrs[] = {
       &c_entry_stub_constant_, &undefined_constant_, &the_hole_constant_,
       &true_constant_,         &false_constant_,     &null_constant_,
       &zero_constant_,         &one_constant_,       &nan_constant_};
   for (size_t i = 0; i < arraysize(ptrs); i++) {
     if (ptrs[i]->is_set()) nodes->push_back(ptrs[i]->get());
   }
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8