[turbofan] Fix typing rule for JSCreateArguments.

src/compiler/typer.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/typer.h"
 
 #include <iomanip>
 
 #include "src/base/flags.h"
 #include "src/bootstrapper.h"
@@ skipping 1098 matching lines @@
   return TypeUnaryOp(node, ToString);
 }
 
 // JS object operators.
 
 
 Type* Typer::Visitor::TypeJSCreate(Node* node) { return Type::Object(); }
 
 
 Type* Typer::Visitor::TypeJSCreateArguments(Node* node) {
-  return Type::OtherObject();
+  switch (CreateArgumentsTypeOf(node->op())) {
+    case CreateArgumentsType::kRestParameter:
+      return Type::Array();
+    case CreateArgumentsType::kMappedArguments:
+    case CreateArgumentsType::kUnmappedArguments:
+      return Type::OtherObject();
+  }
+  UNREACHABLE();
+  return nullptr;
 }
 
 Type* Typer::Visitor::TypeJSCreateArray(Node* node) { return Type::Array(); }
 
 Type* Typer::Visitor::TypeJSCreateClosure(Node* node) {
   return Type::Function();
 }
 
 
 Type* Typer::Visitor::TypeJSCreateIterResultObject(Node* node) {
@@ skipping 865 matching lines @@
 Type* Typer::Visitor::TypeConstant(Handle<Object> value) {
   if (Type::IsInteger(*value)) {
     return Type::Range(value->Number(), value->Number(), zone());
   }
   return Type::NewConstant(value, zone());
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8