[hydrogen] don't bailout assignments to consts

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index b35dc7c145d884c074bd6582419293f7015fd954..a01e41e067951737a1586aab930da7fcbdc4b1a7 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -2310,6 +2310,14 @@ void LCodeGen::DoStoreContextSlot(LStoreContextSlot* instr) {
   Register context = ToRegister(instr->context());
   Register value = ToRegister(instr->value());
   MemOperand target = ContextOperand(context, instr->slot_index());
+
+  Label skip_assignment;
+
+  if (instr->RequiresHoleCheck()) {
+    __ cmp(value, Operand(factory()->the_hole_value()));
+    __ b(ne, &skip_assignment);
+  }
+
   __ str(value, target);
   if (instr->hydrogen()->NeedsWriteBarrier()) {
     HType type = instr->hydrogen()->value()->type();
@@ -2324,6 +2332,8 @@ void LCodeGen::DoStoreContextSlot(LStoreContextSlot* instr) {
                               EMIT_REMEMBERED_SET,
                               check_needed);
   }
+
+  __ bind(&skip_assignment);
 }