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

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index 17afa48914d0e2968be902cb89a4073d5b507f17..e918f8ce6ef4f8a26f7881a90a9ed69a755c11c9 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -4092,7 +4092,14 @@ void LCodeGen::DoCallNewArray(LCallNewArray* instr) {
   DCHECK(ToRegister(instr->result()).is(r0));
 
   __ mov(r0, Operand(instr->arity()));
-  __ LoadRoot(r2, 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.
+    __ Move(r2, instr->hydrogen()->site());
+  } else {
+    __ LoadRoot(r2, Heap::kUndefinedValueRootIndex);
+  }
   ElementsKind kind = instr->hydrogen()->elements_kind();
   AllocationSiteOverrideMode override_mode =
       (AllocationSite::GetMode(kind) == TRACK_ALLOCATION_SITE)