Array() in optimized code can create with wrong ElementsKind in corner cases.

src/mips/lithium-codegen-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.7
 // 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 4049 matching lines @@
   CallCode(stub.GetCode(), RelocInfo::CONSTRUCT_CALL, instr);
 }
 
 
 void LCodeGen::DoCallNewArray(LCallNewArray* instr) {
   DCHECK(ToRegister(instr->context()).is(cp));
   DCHECK(ToRegister(instr->constructor()).is(a1));
   DCHECK(ToRegister(instr->result()).is(v0));
 
   __ li(a0, Operand(instr->arity()));
-  __ LoadRoot(a2, Heap::kUndefinedValueRootIndex);
+  if (instr->arity() == 1) {
+    // We only need the allocation site for the case we have a length argument.
+    // The case may bail out to the runtime, which will determine the correct
+    // elements kind with the site.
+    __ li(a2, instr->hydrogen()->site());
+  } else {
+    __ LoadRoot(a2, Heap::kUndefinedValueRootIndex);
+  }
   ElementsKind kind = instr->hydrogen()->elements_kind();
   AllocationSiteOverrideMode override_mode =
       (AllocationSite::GetMode(kind) == TRACK_ALLOCATION_SITE)
           ? DISABLE_ALLOCATION_SITES
           : DONT_OVERRIDE;
 
   if (instr->arity() == 0) {
     ArrayNoArgumentConstructorStub stub(isolate(), kind, override_mode);
     CallCode(stub.GetCode(), RelocInfo::CONSTRUCT_CALL, instr);
   } else if (instr->arity() == 1) {
@@ skipping 1882 matching lines @@
   __ li(at, scope_info);
   __ Push(at, ToRegister(instr->function()));
   CallRuntime(Runtime::kPushBlockContext, 2, instr);
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal