[crankshaft] Remove dead Variable hole-checking code

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

Index: src/crankshaft/mips/lithium-codegen-mips.cc
diff --git a/src/crankshaft/mips/lithium-codegen-mips.cc b/src/crankshaft/mips/lithium-codegen-mips.cc
index df2f3711850a24fbcabec6af7d45f76a6d92d437..c295ae17f09a03f28111fc87c1181187167b356e 100644
--- a/src/crankshaft/mips/lithium-codegen-mips.cc
+++ b/src/crankshaft/mips/lithium-codegen-mips.cc
@@ -2484,18 +2484,6 @@ void LCodeGen::DoLoadContextSlot(LLoadContextSlot* instr) {
   Register result = ToRegister(instr->result());
 
   __ lw(result, ContextMemOperand(context, instr->slot_index()));
-  if (instr->hydrogen()->RequiresHoleCheck()) {
-    __ LoadRoot(at, Heap::kTheHoleValueRootIndex);
-
-    if (instr->hydrogen()->DeoptimizesOnHole()) {
-      DeoptimizeIf(eq, instr, DeoptimizeReason::kHole, result, Operand(at));
-    } else {
-      Label is_not_hole;
-      __ Branch(&is_not_hole, ne, result, Operand(at));
-      __ LoadRoot(result, Heap::kUndefinedValueRootIndex);
-      __ bind(&is_not_hole);
-    }
-  }
 }
 
 
@@ -2505,19 +2493,6 @@ void LCodeGen::DoStoreContextSlot(LStoreContextSlot* instr) {
   Register scratch = scratch0();
   MemOperand target = ContextMemOperand(context, instr->slot_index());
 
-  Label skip_assignment;
-
-  if (instr->hydrogen()->RequiresHoleCheck()) {
-    __ lw(scratch, target);
-    __ LoadRoot(at, Heap::kTheHoleValueRootIndex);
-
-    if (instr->hydrogen()->DeoptimizesOnHole()) {
-      DeoptimizeIf(eq, instr, DeoptimizeReason::kHole, scratch, Operand(at));
-    } else {
-      __ Branch(&skip_assignment, ne, scratch, Operand(at));
-    }
-  }
-
   __ sw(value, target);
   if (instr->hydrogen()->NeedsWriteBarrier()) {
     SmiCheck check_needed =
@@ -2532,8 +2507,6 @@ void LCodeGen::DoStoreContextSlot(LStoreContextSlot* instr) {
                               EMIT_REMEMBERED_SET,
                               check_needed);
   }
-
-  __ bind(&skip_assignment);
 }