Implement local check elimination on basic blocks.

src/hydrogen-instructions.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 3269 matching lines @@
                                           HValue* context,
                                           int32_t value,
                                           Representation representation,
                                           HInstruction* instruction) {
     HConstant* new_constant =
         HConstant::New(zone, context, value, representation);
     new_constant->InsertBefore(instruction);
     return new_constant;
   }
 
+  static HConstant* CreateAndInsertBefore(Zone* zone,
+                                          Unique<Object> unique,
+                                          bool is_not_in_new_space,
+                                          HInstruction* instruction) {
+    HConstant* new_constant = new(zone) HConstant(unique,
+        Representation::Tagged(), HType::Tagged(), false, is_not_in_new_space,
+        false, false);
+    new_constant->InsertBefore(instruction);
+    return new_constant;
+  }
+
   Handle<Object> handle(Isolate* isolate) {
     if (object_.handle().is_null()) {
       // Default arguments to is_not_in_new_space depend on this heap number
       // to be tenured so that it's guaranteed not to be located in new space.
       object_ = Unique<Object>::CreateUninitialized(
           isolate->factory()->NewNumber(double_value_, TENURED));
     }
     AllowDeferredHandleDereference smi_check;
     ASSERT(has_int32_value_ || !object_.handle()->IsSmi());
     return object_.handle();
@@ skipping 3736 matching lines @@
   virtual bool IsDeletable() const V8_OVERRIDE { return true; }
 };
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_