Liveness analysis for environment slots in Hydrogen

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 1217a4000df42e15b91295e3cdbbe80c76846609..99164df0ed591ec7e394cd1bf00f714015eb5826 100644
--- a/src/x64/lithium-x64.cc
+++ b/src/x64/lithium-x64.cc
@@ -707,6 +707,12 @@ LInstruction* LChunkBuilder::DoDummyUse(HDummyUse* instr) {
 }
 
 
+LInstruction* LChunkBuilder::DoEnvironmentMarker(HEnvironmentMarker* instr) {
+  UNREACHABLE();
+  return NULL;
+}
+
+
 LInstruction* LChunkBuilder::DoSoftDeoptimize(HSoftDeoptimize* instr) {
   return AssignEnvironment(new(zone()) LDeoptimize);
 }