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

src/mips/macro-assembler-mips.cc

Index: src/mips/macro-assembler-mips.cc
diff --git a/src/mips/macro-assembler-mips.cc b/src/mips/macro-assembler-mips.cc
index b7c8509c2a13eb328fa8121b88c7f1656b54e8e7..0afe5157d6742c1128162dcb0ab2842f872d0173 100644
--- a/src/mips/macro-assembler-mips.cc
+++ b/src/mips/macro-assembler-mips.cc
@@ -5511,7 +5511,8 @@ 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 = t1;
   Register  empty_fixed_array_value = t2;
   LoadRoot(empty_fixed_array_value, Heap::kEmptyFixedArrayRootIndex);
   Label next, start;
@@ -5525,6 +5526,7 @@ void MacroAssembler::CheckEnumCache(Register null_value, Label* call_runtime) {
   Branch(
       call_runtime, eq, a3, Operand(Smi::FromInt(kInvalidEnumCacheSentinel)));
 
+  LoadRoot(null_value, Heap::kNullValueRootIndex);
   jmp(&start);
 
   bind(&next);