[for-in] Sanitize for-in optimizations and fix bailout points.

src/arm/macro-assembler-arm.cc

Index: src/arm/macro-assembler-arm.cc
diff --git a/src/arm/macro-assembler-arm.cc b/src/arm/macro-assembler-arm.cc
index 6b729db86071751d9955f80f4b1d91573bcfbba6..bec9962f481dcff3f5bc17b25fdd8021cc55cc83 100644
--- a/src/arm/macro-assembler-arm.cc
+++ b/src/arm/macro-assembler-arm.cc
@@ -3384,7 +3384,8 @@ void MacroAssembler::LoadAccessor(Register dst, Register holder,
 }
 
 
-void MacroAssembler::CheckEnumCache(Register null_value, Label* call_runtime) {
+void MacroAssembler::CheckEnumCache(Label* call_runtime) {
+  Register null_value = r5;
   Register  empty_fixed_array_value = r6;
   LoadRoot(empty_fixed_array_value, Heap::kEmptyFixedArrayRootIndex);
   Label next, start;
@@ -3398,6 +3399,7 @@ void MacroAssembler::CheckEnumCache(Register null_value, Label* call_runtime) {
   cmp(r3, Operand(Smi::FromInt(kInvalidEnumCacheSentinel)));
   b(eq, call_runtime);
 
+  LoadRoot(null_value, Heap::kNullValueRootIndex);
   jmp(&start);
 
   bind(&next);