[turbofan] support small immediates

test/cctest/compiler/test-jump-threading.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/v8.h"
 #include "test/cctest/cctest.h"
 
 #include "src/compiler/instruction.h"
 #include "src/compiler/instruction-codes.h"
 #include "src/compiler/jump-threading.h"
@@ skipping 48 matching lines @@
     Start();
     sequence_.AddInstruction(Instruction::New(main_zone(), kArchNop));
     int index = static_cast<int>(sequence_.instructions().size()) - 1;
     AddGapMove(index, RegisterOperand::New(main_zone(), 13),
                RegisterOperand::New(main_zone(), 13));
   }
   void NonRedundantMoves() {
     Start();
     sequence_.AddInstruction(Instruction::New(main_zone(), kArchNop));
     int index = static_cast<int>(sequence_.instructions().size()) - 1;
-    AddGapMove(index, ImmediateOperand::New(main_zone(), 11),
+    AddGapMove(index, ConstantOperand::New(main_zone(), 11),
                RegisterOperand::New(main_zone(), 11));
   }
   void Other() {
     Start();
     sequence_.AddInstruction(Instruction::New(main_zone(), 155));
   }
   void End() {
     Start();
     sequence_.EndBlock(current_->rpo_number());
     current_ = NULL;
     rpo_number_ = RpoNumber::FromInt(rpo_number_.ToInt() + 1);
   }
   InstructionOperand UseRpo(int num) {
-    int index = sequence_.AddImmediate(Constant(RpoNumber::FromInt(num)));
-    return ImmediateOperand(index);
+    return sequence_.AddImmediate(Constant(RpoNumber::FromInt(num)));
   }
   void Start(bool deferred = false) {
     if (current_ == NULL) {
       current_ = new (main_zone())
           InstructionBlock(main_zone(), rpo_number_, RpoNumber::Invalid(),
                            RpoNumber::Invalid(), deferred);
       blocks_.push_back(current_);
       sequence_.StartBlock(rpo_number_);
     }
   }
@@ skipping 663 matching lines @@
         for (int k = 4; k < 5; k++) assembly[k]--;
       }
       CheckAssemblyOrder(code, 5, assembly);
     }
   }
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8