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

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
===================================================================
--- src/x64/lithium-codegen-x64.cc	(revision 11356)
+++ src/x64/lithium-codegen-x64.cc	(working copy)
@@ -2016,8 +2016,7 @@
                     RECORD_SAFEPOINT_WITH_REGISTERS,
                     2);
     ASSERT(delta == masm_->SizeOfCodeGeneratedSince(map_check));
-    ASSERT(instr->HasDeoptimizationEnvironment());
-    LEnvironment* env = instr->deoptimization_environment();
+    LEnvironment* env = instr->GetDeferredLazyDeoptimizationEnvironment();
     safepoints_.RecordLazyDeoptimizationIndex(env->deoptimization_index());
     // Move result to a register that survives the end of the
     // PushSafepointRegisterScope.
@@ -2626,7 +2625,7 @@
 
   // Invoke the function.
   __ bind(&invoke);
-  ASSERT(instr->HasPointerMap() && instr->HasDeoptimizationEnvironment());
+  ASSERT(instr->HasPointerMap());
   LPointerMap* pointers = instr->pointer_map();
   RecordPosition(pointers->position());
   SafepointGenerator safepoint_generator(
@@ -3183,7 +3182,6 @@
 void LCodeGen::DoInvokeFunction(LInvokeFunction* instr) {
   ASSERT(ToRegister(instr->function()).is(rdi));
   ASSERT(instr->HasPointerMap());
-  ASSERT(instr->HasDeoptimizationEnvironment());
   LPointerMap* pointers = instr->pointer_map();
   RecordPosition(pointers->position());
   SafepointGenerator generator(this, pointers, Safepoint::kLazyDeopt);
@@ -4605,7 +4603,7 @@
   LOperand* key = instr->key();
   EmitPushTaggedOperand(obj);
   EmitPushTaggedOperand(key);
-  ASSERT(instr->HasPointerMap() && instr->HasDeoptimizationEnvironment());
+  ASSERT(instr->HasPointerMap());
   LPointerMap* pointers = instr->pointer_map();
   RecordPosition(pointers->position());
   // Create safepoint generator that will also ensure enough space in the
@@ -4623,7 +4621,7 @@
   LOperand* key = instr->key();
   EmitPushTaggedOperand(key);
   EmitPushTaggedOperand(obj);
-  ASSERT(instr->HasPointerMap() && instr->HasDeoptimizationEnvironment());
+  ASSERT(instr->HasPointerMap());
   LPointerMap* pointers = instr->pointer_map();
   RecordPosition(pointers->position());
   SafepointGenerator safepoint_generator(