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

BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/android/config.gni")
 import("//build/config/arm.gni")
 import("//build/config/dcheck_always_on.gni")
 import("//build/config/mips.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 
@@ skipping 1197 matching lines @@
     "src/identity-map.cc",
     "src/identity-map.h",
     "src/interface-descriptors.cc",
     "src/interface-descriptors.h",
     "src/interpreter/bytecode-array-builder.cc",
     "src/interpreter/bytecode-array-builder.h",
     "src/interpreter/bytecode-array-iterator.cc",
     "src/interpreter/bytecode-array-iterator.h",
     "src/interpreter/bytecode-array-writer.cc",
     "src/interpreter/bytecode-array-writer.h",
+    "src/interpreter/bytecode-dead-code-optimizer.cc",
+    "src/interpreter/bytecode-dead-code-optimizer.h",
     "src/interpreter/bytecode-generator.cc",
     "src/interpreter/bytecode-generator.h",
     "src/interpreter/bytecode-label.h",
     "src/interpreter/bytecode-peephole-optimizer.cc",
     "src/interpreter/bytecode-peephole-optimizer.h",
     "src/interpreter/bytecode-pipeline.cc",
     "src/interpreter/bytecode-pipeline.h",
     "src/interpreter/bytecode-register-allocator.cc",
     "src/interpreter/bytecode-register-allocator.h",
     "src/interpreter/bytecode-register-optimizer.cc",
@@ skipping 1015 matching lines @@
 
   deps = [
     ":fuzzer_support",
   ]
 
   configs = [ ":internal_config" ]
 }
 
 v8_fuzzer("wasm_asmjs_fuzzer") {
 }