Allow specifying base offset when constructing Keyed hydrogen instructions

src/x64/lithium-x64.cc

Index: src/x64/lithium-x64.cc
diff --git a/src/x64/lithium-x64.cc b/src/x64/lithium-x64.cc
index cbade8a7d95fac4b2309b7e1fd648a3f17ba1454..ec677ee3cc691b1d9c1f65436bb9ff6643bc9ff7 100644
--- a/src/x64/lithium-x64.cc
+++ b/src/x64/lithium-x64.cc
@@ -371,7 +371,7 @@ void LLoadKeyed::PrintDataTo(StringStream* stream) {
   stream->Add("[");
   key()->PrintTo(stream);
   if (hydrogen()->IsDehoisted()) {
-    stream->Add(" + %d]", additional_index());
+    stream->Add(" + %d]", base_offset());
   } else {
     stream->Add("]");
   }
@@ -383,7 +383,7 @@ void LStoreKeyed::PrintDataTo(StringStream* stream) {
   stream->Add("[");
   key()->PrintTo(stream);
   if (hydrogen()->IsDehoisted()) {
-    stream->Add(" + %d] <-", additional_index());
+    stream->Add(" + %d] <-", base_offset());
   } else {
     stream->Add("] <- ");
   }