Support Smi->Double->HeapObject transitions in constructed Arrays.

src/x64/builtins-x64.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 1287 matching lines @@
   // rbx: JSArray
   // rdx: location of the first array element
   // r9: location of the last argument
   // esp[0]: return address
   // esp[8]: last argument
   Label loop, entry;
   __ movq(rcx, rax);
   __ jmp(&entry);
   __ bind(&loop);
   __ movq(kScratchRegister, Operand(r9, rcx, times_pointer_size, 0));
+  if (FLAG_smi_only_arrays) {
+    __ JumpIfNotSmi(kScratchRegister, call_generic_code);
+  }
   __ movq(Operand(rdx, 0), kScratchRegister);
   __ addq(rdx, Immediate(kPointerSize));
   __ bind(&entry);
   __ decq(rcx);
   __ j(greater_equal, &loop);
 
   // Remove caller arguments from the stack and return.
   // rax: argc
   // rbx: JSArray
   // esp[0]: return address
@@ skipping 255 matching lines @@
   Deoptimizer::EntryGenerator generator(masm, Deoptimizer::OSR);
   generator.Generate();
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64