Fix mistake in ARM version of string length stub.

src/ic-arm.cc

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 156 matching lines @@
 
   __ ldr(r0, MemOperand(sp, 0));
 
   // Check that the receiver isn't a smi.
   __ tst(r0, Operand(kSmiTagMask));
   __ b(eq, &miss);
 
   // Check that the object is a string.
   __ ldr(r1, FieldMemOperand(r0, HeapObject::kMapOffset));
   __ ldrb(r1, FieldMemOperand(r1, Map::kInstanceTypeOffset));
+  __ mov(r3, Operand(r1));
   __ and_(r1, r1, Operand(kIsNotStringMask));
   // The cast is to resolve the overload for the argument of 0x0.
   __ cmp(r1, Operand(static_cast<int32_t>(kStringTag)));
   __ b(ne, &miss);
 
-  __ and_(r1, r1, Operand(kStringSizeMask));
+  __ and_(r1, r3, Operand(kStringSizeMask));
   __ add(r1, r1, Operand(String::kHashShift));
   // Load length directly from the string.
   __ ldr(r0, FieldMemOperand(r0, String::kLengthOffset));
   __ mov(r0, Operand(r0, LSR, r1));
   __ mov(r0, Operand(r0, LSL, kSmiTagSize));
   __ Ret();
 
   // Cache miss: Jump to runtime.
   __ bind(&miss);
   Handle<Code> ic(Builtins::builtin(Builtins::LoadIC_Miss));
@@ skipping 329 matching lines @@
 
   // Perform tail call to the entry.
   __ TailCallRuntime(f, 3);
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal