[turbofan] Decouple inlining and native 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/node-matchers.h"
@@ skipping 16 matching lines @@
   }
   return NoChange();
 }
 
 
 MaybeHandle<Context> JSContextSpecialization::GetSpecializationContext(
     Node* node) {
   DCHECK(node->opcode() == IrOpcode::kJSLoadContext ||
          node->opcode() == IrOpcode::kJSStoreContext);
   Node* const object = NodeProperties::GetValueInput(node, 0);
-  switch (object->opcode()) {
-    case IrOpcode::kHeapConstant:
-      return Handle<Context>::cast(OpParameter<Handle<HeapObject>>(object));
-    case IrOpcode::kParameter: {
-      Node* const start = NodeProperties::GetValueInput(object, 0);
-      DCHECK_EQ(IrOpcode::kStart, start->opcode());
-      int const index = ParameterIndexOf(object->op());
-      // The context is always the last parameter to a JavaScript function, and
-      // {Parameter} indices start at -1, so value outputs of {Start} look like
-      // this: closure, receiver, param0, ..., paramN, context.
-      if (index == start->op()->ValueOutputCount() - 2) {
-        return context();
-      }
-      break;
-    }
-    default:
-      break;
-  }
-  return MaybeHandle<Context>();
+  return NodeProperties::GetSpecializationContext(object, context());
 }
 
 
 Reduction JSContextSpecialization::ReduceJSLoadContext(Node* node) {
   DCHECK_EQ(IrOpcode::kJSLoadContext, node->opcode());
 
   // Get the specialization context from the node.
   Handle<Context> context;
   if (!GetSpecializationContext(node).ToHandle(&context)) return NoChange();
 
@@ skipping 67 matching lines @@
 }
 
 
 JSOperatorBuilder* JSContextSpecialization::javascript() const {
   return jsgraph()->javascript();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8