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

src/mips64/macro-assembler-mips64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <limits.h>  // For LONG_MIN, LONG_MAX.
 
 #if V8_TARGET_ARCH_MIPS64
 
 #include "src/base/division-by-constant.h"
 #include "src/bootstrapper.h"
@@ skipping 6221 matching lines @@
   ld(dst, FieldMemOperand(holder, HeapObject::kMapOffset));
   LoadInstanceDescriptors(dst, dst);
   ld(dst,
      FieldMemOperand(dst, DescriptorArray::GetValueOffset(accessor_index)));
   int offset = accessor == ACCESSOR_GETTER ? AccessorPair::kGetterOffset
                                            : AccessorPair::kSetterOffset;
   ld(dst, FieldMemOperand(dst, offset));
 }
 
 
-void MacroAssembler::CheckEnumCache(Register null_value, Label* call_runtime) {
+void MacroAssembler::CheckEnumCache(Label* call_runtime) {
+  Register null_value = a5;
   Register  empty_fixed_array_value = a6;
   LoadRoot(empty_fixed_array_value, Heap::kEmptyFixedArrayRootIndex);
   Label next, start;
   mov(a2, a0);
 
   // Check if the enum length field is properly initialized, indicating that
   // there is an enum cache.
   ld(a1, FieldMemOperand(a2, HeapObject::kMapOffset));
 
   EnumLength(a3, a1);
   Branch(
       call_runtime, eq, a3, Operand(Smi::FromInt(kInvalidEnumCacheSentinel)));
 
+  LoadRoot(null_value, Heap::kNullValueRootIndex);
   jmp(&start);
 
   bind(&next);
   ld(a1, FieldMemOperand(a2, HeapObject::kMapOffset));
 
   // For all objects but the receiver, check that the cache is empty.
   EnumLength(a3, a1);
   Branch(call_runtime, ne, a3, Operand(Smi::FromInt(0)));
 
   bind(&start);
@@ skipping 227 matching lines @@
   if (mag.shift > 0) sra(result, result, mag.shift);
   srl(at, dividend, 31);
   Addu(result, result, Operand(at));
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS64