[turbofan] Proper dead code elimination as regular reducer.

test/unittests/compiler/node-test-utils.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 "test/unittests/compiler/node-test-utils.h"
 
 #include <vector>
 
 #include "src/assembler.h"
 #include "src/compiler/js-operator.h"
@@ skipping 1360 matching lines @@
                                  "input", input_matcher_, listener));
   }
 
  private:
   const Matcher<Node*> input_matcher_;
 };
 
 }  // namespace
 
 
+Matcher<Node*> IsDead() {
+  return MakeMatcher(new NodeMatcher(IrOpcode::kDead));
+}
+
+
 Matcher<Node*> IsEnd(const Matcher<Node*>& control0_matcher) {
   return MakeMatcher(new IsControl1Matcher(IrOpcode::kEnd, control0_matcher));
 }
 
 
 Matcher<Node*> IsEnd(const Matcher<Node*>& control0_matcher,
                      const Matcher<Node*>& control1_matcher) {
   return MakeMatcher(new IsControl2Matcher(IrOpcode::kEnd, control0_matcher,
                                            control1_matcher));
 }
@@ skipping 458 matching lines @@
 IS_UNOP_MATCHER(NumberToInt32)
 IS_UNOP_MATCHER(NumberToUint32)
 IS_UNOP_MATCHER(ObjectIsSmi)
 IS_UNOP_MATCHER(ObjectIsNonNegativeSmi)
 IS_UNOP_MATCHER(Word32Clz)
 #undef IS_UNOP_MATCHER
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8