Improve dead code elimination by transitively marking live code and removing all dead code. Replace…

src/hydrogen-instructions.cc

Index: src/hydrogen-instructions.cc
diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc
index f38fb7d5e3d4312383c198cf23b25a7cf2f8f602..f191323ece7130f63ae219623d73f577a3a2f013 100644
--- a/src/hydrogen-instructions.cc
+++ b/src/hydrogen-instructions.cc
@@ -648,7 +648,6 @@ void HValue::SetOperandAt(int index, HValue* value) {
 void HValue::DeleteAndReplaceWith(HValue* other) {
   // We replace all uses first, so Delete can assert that there are none.
   if (other != NULL) ReplaceAllUsesWith(other);
-  ASSERT(HasNoUses());
   Kill();
   DeleteFromGraph();
 }
@@ -1899,9 +1898,7 @@ void HPhi::PrintTo(StringStream* stream) {
               int32_non_phi_uses() + int32_indirect_uses(),
               double_non_phi_uses() + double_indirect_uses(),
               tagged_non_phi_uses() + tagged_indirect_uses());
-  stream->Add("%s%s]",
-              is_live() ? "_live" : "",
-              IsConvertibleToInteger() ? "" : "_ncti");
+  stream->Add("%s]", IsConvertibleToInteger() ? "" : "_ncti");
 }