Revert remove dead hole check logic

src/crankshaft/arm/lithium-codegen-arm.cc

Index: src/crankshaft/arm/lithium-codegen-arm.cc
diff --git a/src/crankshaft/arm/lithium-codegen-arm.cc b/src/crankshaft/arm/lithium-codegen-arm.cc
index 10b0f849412f5073151678ee20b79beb5fc773e1..07accfbb080212d447f326a05399a5e6aaba13c9 100644
--- a/src/crankshaft/arm/lithium-codegen-arm.cc
+++ b/src/crankshaft/arm/lithium-codegen-arm.cc
@@ -2567,6 +2567,15 @@ void LCodeGen::DoLoadContextSlot(LLoadContextSlot* instr) {
   Register context = ToRegister(instr->context());
   Register result = ToRegister(instr->result());
   __ ldr(result, ContextMemOperand(context, instr->slot_index()));
+  if (instr->hydrogen()->RequiresHoleCheck()) {
+    __ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
+    __ cmp(result, ip);
+    if (instr->hydrogen()->DeoptimizesOnHole()) {
+      DeoptimizeIf(eq, instr, DeoptimizeReason::kHole);
+    } else {
+      __ mov(result, Operand(factory()->undefined_value()), LeaveCC, eq);
+    }
+  }
 }
 
 
@@ -2576,6 +2585,19 @@ void LCodeGen::DoStoreContextSlot(LStoreContextSlot* instr) {
   Register scratch = scratch0();
   MemOperand target = ContextMemOperand(context, instr->slot_index());
 
+  Label skip_assignment;
+
+  if (instr->hydrogen()->RequiresHoleCheck()) {
+    __ ldr(scratch, target);
+    __ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
+    __ cmp(scratch, ip);
+    if (instr->hydrogen()->DeoptimizesOnHole()) {
+      DeoptimizeIf(eq, instr, DeoptimizeReason::kHole);
+    } else {
+      __ b(ne, &skip_assignment);
+    }
+  }
+
   __ str(value, target);
   if (instr->hydrogen()->NeedsWriteBarrier()) {
     SmiCheck check_needed =
@@ -2590,6 +2612,8 @@ void LCodeGen::DoStoreContextSlot(LStoreContextSlot* instr) {
                               EMIT_REMEMBERED_SET,
                               check_needed);
   }
+
+  __ bind(&skip_assignment);
 }