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

src/arm/macro-assembler-arm.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_ARM
 
 #include "src/base/bits.h"
 #include "src/base/division-by-constant.h"
@@ skipping 3366 matching lines @@
   ldr(dst, FieldMemOperand(holder, HeapObject::kMapOffset));
   LoadInstanceDescriptors(dst, dst);
   ldr(dst,
       FieldMemOperand(dst, DescriptorArray::GetValueOffset(accessor_index)));
   int offset = accessor == ACCESSOR_GETTER ? AccessorPair::kGetterOffset
                                            : AccessorPair::kSetterOffset;
   ldr(dst, FieldMemOperand(dst, offset));
 }
 
 
-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;
   mov(r2, r0);
 
   // Check if the enum length field is properly initialized, indicating that
   // there is an enum cache.
   ldr(r1, FieldMemOperand(r2, HeapObject::kMapOffset));
 
   EnumLength(r3, r1);
   cmp(r3, Operand(Smi::FromInt(kInvalidEnumCacheSentinel)));
   b(eq, call_runtime);
 
+  LoadRoot(null_value, Heap::kNullValueRootIndex);
   jmp(&start);
 
   bind(&next);
   ldr(r1, FieldMemOperand(r2, HeapObject::kMapOffset));
 
   // For all objects but the receiver, check that the cache is empty.
   EnumLength(r3, r1);
   cmp(r3, Operand(Smi::FromInt(0)));
   b(ne, call_runtime);
 
@@ skipping 194 matching lines @@
     }
   }
   if (mag.shift > 0) mov(result, Operand(result, ASR, mag.shift));
   add(result, result, Operand(dividend, LSR, 31));
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM