Handle array construction in native code (x64 version)

src/x64/stub-cache-x64.cc

 // Copyright 2009 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 1733 matching lines @@
   // code for the function thereby hitting the break points.
   __ movq(rbx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
   __ movq(rbx, FieldOperand(rbx, SharedFunctionInfo::kDebugInfoOffset));
   __ cmpq(rbx, r8);
   __ j(not_equal, &generic_stub_call);
 #endif
 
   // Load the initial map and verify that it is in fact a map.
   __ movq(rbx, FieldOperand(rdi, JSFunction::kPrototypeOrInitialMapOffset));
   // Will both indicate a NULL and a Smi.
+  ASSERT(kSmiTag == 0);
   __ JumpIfSmi(rbx, &generic_stub_call);
   __ CmpObjectType(rbx, MAP_TYPE, rcx);
   __ j(not_equal, &generic_stub_call);
 
 #ifdef DEBUG
   // Cannot construct functions this way.
   // rdi: constructor
   // rbx: initial map
   __ CmpInstanceType(rbx, JS_FUNCTION_TYPE);
   __ Assert(not_equal, "Function constructed by construct stub.");
@@ skipping 86 matching lines @@
   __ Jump(generic_construct_stub, RelocInfo::CODE_TARGET);
 
   // Return the generated code.
   return GetCode();
 }
 
 
 #undef __
 
 } }  // namespace v8::internal