Fix cow fixed array map check in optimized arm code.

src/arm/lithium-codegen-arm.cc

 // Copyright 2011 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 2392 matching lines @@
 
   __ ldr(result, FieldMemOperand(input, JSObject::kElementsOffset));
   if (FLAG_debug_code) {
     Label done;
     __ ldr(scratch, FieldMemOperand(result, HeapObject::kMapOffset));
     __ LoadRoot(ip, Heap::kFixedArrayMapRootIndex);
     __ cmp(scratch, ip);
     __ b(eq, &done);
     __ LoadRoot(ip, Heap::kFixedCOWArrayMapRootIndex);
     __ cmp(scratch, ip);
+    __ b(eq, &done);
     __ ldr(scratch, FieldMemOperand(result, HeapObject::kMapOffset));
     __ ldrb(scratch, FieldMemOperand(scratch, Map::kInstanceTypeOffset));
     __ sub(scratch, scratch, Operand(FIRST_EXTERNAL_ARRAY_TYPE));
     __ cmp(scratch, Operand(kExternalArrayTypeCount));
     __ Check(cc, "Check for fast elements failed.");
     __ bind(&done);
   }
 }
 
 
@@ skipping 1780 matching lines @@
   ASSERT(!environment->HasBeenRegistered());
   RegisterEnvironmentForDeoptimization(environment);
   ASSERT(osr_pc_offset_ == -1);
   osr_pc_offset_ = masm()->pc_offset();
 }
 
 
 #undef __
 
 } }  // namespace v8::internal