[turbofan] Specialize to closure with function context specialization.

src/compiler/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/common-operator.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/js-operator.h"
+#include "src/compiler/linkage.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 #include "src/contexts.h"
 #include "src/objects-inl.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 Reduction JSContextSpecialization::Reduce(Node* node) {
   switch (node->opcode()) {
+    case IrOpcode::kParameter:
+      return ReduceParameter(node);
     case IrOpcode::kJSLoadContext:
       return ReduceJSLoadContext(node);
     case IrOpcode::kJSStoreContext:
       return ReduceJSStoreContext(node);
     default:
       break;
   }
   return NoChange();
 }
 
+Reduction JSContextSpecialization::ReduceParameter(Node* node) {
+  DCHECK_EQ(IrOpcode::kParameter, node->opcode());
+  int const index = ParameterIndexOf(node->op());
+  if (index == Linkage::kJSCallClosureParamIndex) {
+    // Constant-fold the function parameter {node}.
+    Handle<JSFunction> function;
+    if (closure().ToHandle(&function)) {
+      Node* value = jsgraph()->HeapConstant(function);
+      return Replace(value);
+    }
+  }
+  return NoChange();
+}
+
 Reduction JSContextSpecialization::SimplifyJSLoadContext(Node* node,
                                                          Node* new_context,
                                                          size_t new_depth) {
   DCHECK_EQ(IrOpcode::kJSLoadContext, node->opcode());
   const ContextAccess& access = ContextAccessOf(node->op());
   DCHECK_LE(new_depth, access.depth());
 
   if (new_depth == access.depth() &&
       new_context == NodeProperties::GetContextInput(node)) {
     return NoChange();
@@ skipping 105 matching lines @@
 }
 
 
 JSOperatorBuilder* JSContextSpecialization::javascript() const {
   return jsgraph()->javascript();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8