Replace ToAsciiVector and ToUC16Vector with single function that returns a tagged value.

src/hydrogen-instructions.cc

Index: src/hydrogen-instructions.cc
diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc
index 176218616e2917ff93e86e8ed50013fb0cc4e053..df22bfde93b5a0ffb6646e8ab6b0ae93f3f6d812 100644
--- a/src/hydrogen-instructions.cc
+++ b/src/hydrogen-instructions.cc
@@ -778,7 +778,8 @@ void HHasInstanceTypeAndBranch::PrintDataTo(StringStream* stream) {
 void HTypeofIsAndBranch::PrintDataTo(StringStream* stream) {
   value()->PrintNameTo(stream);
   stream->Add(" == ");
-  stream->Add(type_literal_->ToAsciiVector());
+  AssertNoAllocation no_alloc;
+  stream->Add(type_literal_->GetFlatContent(no_alloc).ToAsciiVector());
 }