Reduce size of LIR instruction by one word and remove dead code.

src/x64/lithium-x64.cc

Index: src/x64/lithium-x64.cc
===================================================================
--- src/x64/lithium-x64.cc	(revision 11356)
+++ src/x64/lithium-x64.cc	(working copy)
@@ -727,22 +727,6 @@
 }
 
 
-LInstruction* LChunkBuilder::SetInstructionPendingDeoptimizationEnvironment(
-    LInstruction* instr, int ast_id) {
-  ASSERT(instruction_pending_deoptimization_environment_ == NULL);
-  ASSERT(pending_deoptimization_ast_id_ == AstNode::kNoNumber);
-  instruction_pending_deoptimization_environment_ = instr;
-  pending_deoptimization_ast_id_ = ast_id;
-  return instr;
-}
-
-
-void LChunkBuilder::ClearInstructionPendingDeoptimizationEnvironment() {
-  instruction_pending_deoptimization_environment_ = NULL;
-  pending_deoptimization_ast_id_ = AstNode::kNoNumber;
-}
-
-
 LInstruction* LChunkBuilder::MarkAsCall(LInstruction* instr,
                                         HInstruction* hinstr,
                                         CanDeoptimize can_deoptimize) {
@@ -755,8 +739,10 @@
   if (hinstr->HasObservableSideEffects()) {
     ASSERT(hinstr->next()->IsSimulate());
     HSimulate* sim = HSimulate::cast(hinstr->next());
-    instr = SetInstructionPendingDeoptimizationEnvironment(
-        instr, sim->ast_id());
+    ASSERT(instruction_pending_deoptimization_environment_ == NULL);
+    ASSERT(pending_deoptimization_ast_id_ == AstNode::kNoNumber);
+    instruction_pending_deoptimization_environment_ = instr;
+    pending_deoptimization_ast_id_ = sim->ast_id();
   }
 
   // If instruction does not have side-effects lazy deoptimization
@@ -774,12 +760,6 @@
 }
 
 
-LInstruction* LChunkBuilder::MarkAsSaveDoubles(LInstruction* instr) {
-  instr->MarkAsSaveDoubles();
-  return instr;
-}
-
-
 LInstruction* LChunkBuilder::AssignPointerMap(LInstruction* instr) {
   ASSERT(!instr->HasPointerMap());
   instr->set_pointer_map(new(zone()) LPointerMap(position_));
@@ -2241,9 +2221,12 @@
   if (pending_deoptimization_ast_id_ == instr->ast_id()) {
     LLazyBailout* lazy_bailout = new(zone()) LLazyBailout;
     LInstruction* result = AssignEnvironment(lazy_bailout);
+    // Store the lazy deopt environment with the instruction if needed. Right
+    // now it is only used for LInstanceOfKnownGlobal.
     instruction_pending_deoptimization_environment_->
-        set_deoptimization_environment(result->environment());
-    ClearInstructionPendingDeoptimizationEnvironment();
+        SetDeferredLazyDeoptimizationEnvironment(result->environment());
+    instruction_pending_deoptimization_environment_ = NULL;
+    pending_deoptimization_ast_id_ = AstNode::kNoNumber;
     return result;
   }