Fix ARM bug introduced in r12604 that caused crashes on ARM

src/arm/stub-cache-arm.cc

 // Copyright 2012 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 4668 matching lines @@
   if (grow_mode == ALLOW_JSARRAY_GROWTH) {
     __ b(hs, &grow);
   } else {
     __ b(hs, &miss_force_generic);
   }
 
   __ bind(&finish_store);
   __ StoreNumberToDoubleElements(value_reg,
                                  key_reg,
                                  receiver_reg,
+                                 // All registers after this are overwritten.
                                  elements_reg,
                                  scratch1,
                                  scratch2,
                                  scratch3,
                                  scratch4,
                                  &transition_elements_kind);
   __ Ret();
 
   // Handle store cache miss, replacing the ic with the generic stub.
   __ bind(&miss_force_generic);
@@ skipping 74 matching lines @@
     __ Jump(ic_slow, RelocInfo::CODE_TARGET);
   }
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM