[Interpreter] Add a simple dead-code elimination bytecode optimizer.

test/cctest/interpreter/test-interpreter.cc

 // Copyright 2015 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 "src/execution.h"
 #include "src/handles.h"
 #include "src/interpreter/bytecode-array-builder.h"
 #include "src/interpreter/bytecode-array-iterator.h"
@@ skipping 1035 matching lines @@
   Handle<Object> return_value = callable().ToHandleChecked();
   CHECK_EQ(Smi::cast(*return_value)->value(), 7);
 }
 
 TEST(InterpreterJumpConstantWith16BitOperand) {
   HandleAndZoneScope handles;
   BytecodeArrayBuilder builder(handles.main_isolate(), handles.main_zone(), 1,
                                0, 257);
 
   Register reg(0), scratch(256);
-  BytecodeLabel done;
+  BytecodeLabel done, fake;
 
   builder.LoadLiteral(Smi::FromInt(0));
   builder.StoreAccumulatorInRegister(reg);
   // Consume all 8-bit operands
   for (int i = 1; i <= 256; i++) {
     builder.LoadLiteral(handles.main_isolate()->factory()->NewNumber(i));
     builder.BinaryOperation(Token::Value::ADD, reg);
     builder.StoreAccumulatorInRegister(reg);
   }
   builder.Jump(&done);
 
   // Emit more than 16-bit immediate operands worth of code to jump over.
+  builder.Bind(&fake);
   for (int i = 0; i < 6600; i++) {
     builder.LoadLiteral(Smi::FromInt(0));                 // 1-byte
     builder.BinaryOperation(Token::Value::ADD, scratch);  // 4-bytes
     builder.StoreAccumulatorInRegister(scratch);          // 4-bytes
     builder.MoveRegister(scratch, reg);                   // 6-bytes
   }
   builder.Bind(&done);
   builder.LoadAccumulatorWithRegister(reg);
   builder.Return();
 
@@ skipping 3114 matching lines @@
     Handle<i::Object> return_value = callable().ToHandleChecked();
     CHECK(return_value->SameValue(*tests[i].second));
   }
 
   FLAG_ignition_generators = old_flag;
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8