Remove HIsNilAndBranch (it's now unused)

src/hydrogen-instructions.cc

Index: src/hydrogen-instructions.cc
diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc
index 78e1229de643102fc206da50dc1e4f944ae46b14..d18e54383fe0a6d6a0231adbee8c281041666743 100644
--- a/src/hydrogen-instructions.cc
+++ b/src/hydrogen-instructions.cc
@@ -1254,14 +1254,6 @@ void HUnaryControlInstruction::PrintDataTo(StringStream* stream) {
 }
 
 
-void HIsNilAndBranch::PrintDataTo(StringStream* stream) {
-  value()->PrintNameTo(stream);
-  stream->Add(kind() == kStrictEquality ? " === " : " == ");
-  stream->Add(nil() == kNullValue ? "null" : "undefined");
-  HControlInstruction::PrintDataTo(stream);
-}
-
-
 void HReturn::PrintDataTo(StringStream* stream) {
   value()->PrintNameTo(stream);
   stream->Add(" (pop ");