[Torque] port Array.isArray to torque

Bug: v8:9891
Change-Id: I5a9600b44c2363cc9681976e4ed2b86eccf35830
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1869581
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64493}

BUILD.gn

@@ -928,6 +928,7 @@ torque_files = [
   "src/builtins/array-find.tq",
   "src/builtins/array-findindex.tq",
   "src/builtins/array-foreach.tq",
+  "src/builtins/array-isarray.tq",
   "src/builtins/array-join.tq",
   "src/builtins/array-lastindexof.tq",
   "src/builtins/array-map.tq",

src/builtins/array-isarray.tq

@@ -0,0 +1,27 @@
+// Copyright 2019 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.
+
+namespace runtime {
+  extern runtime ArrayIsArray(implicit context: Context)(JSAny): JSAny;
+}  // namespace runtime
+
+namespace array {
+  // ES #sec-array.isarray
+  javascript builtin ArrayIsArray(js-implicit context: Context)(arg: JSAny):
+      JSAny {
+    // 1. Return ? IsArray(arg).
+    typeswitch (arg) {
+      case (JSArray): {
+        return True;
+      }
+      case (JSProxy): {
+        // TODO(verwaest): Handle proxies in-place
+        return runtime::ArrayIsArray(arg);
+      }
+      case (JSAny): {
+        return False;
+      }
+    }
+  }
+}  // namespace array

src/builtins/builtins-array-gen.cc

@@ -774,31 +774,6 @@ TF_BUILTIN(TypedArrayPrototypeMap, ArrayBuiltinsAssembler) {
       &ArrayBuiltinsAssembler::TypedArrayMapProcessor);
 }
 
-TF_BUILTIN(ArrayIsArray, CodeStubAssembler) {
-  TNode<Object> object = CAST(Parameter(Descriptor::kArg));
-  TNode<Context> context = CAST(Parameter(Descriptor::kContext));
-
-  Label call_runtime(this), return_true(this), return_false(this);
-
-  GotoIf(TaggedIsSmi(object), &return_false);
-  TNode<Uint16T> instance_type = LoadInstanceType(CAST(object));
-
-  GotoIf(InstanceTypeEqual(instance_type, JS_ARRAY_TYPE), &return_true);
-
-  // TODO(verwaest): Handle proxies in-place.
-  Branch(InstanceTypeEqual(instance_type, JS_PROXY_TYPE), &call_runtime,
-         &return_false);
-
-  BIND(&return_true);
-  Return(TrueConstant());
-
-  BIND(&return_false);
-  Return(FalseConstant());
-
-  BIND(&call_runtime);
-  Return(CallRuntime(Runtime::kArrayIsArray, context, object));
-}
-
 class ArrayIncludesIndexofAssembler : public CodeStubAssembler {
  public:
   explicit ArrayIncludesIndexofAssembler(compiler::CodeAssemblerState* state)

src/builtins/builtins-definitions.h

@@ -313,8 +313,6 @@ namespace internal {
       ArraySingleArgumentConstructor)                                          \
   TFC(ArrayNArgumentsConstructor, ArrayNArgumentsConstructor)                  \
   CPP(ArrayConcat)                                                             \
-  /* ES6 #sec-array.isarray */                                                 \
-  TFJ(ArrayIsArray, 1, kReceiver, kArg)                                        \
   /* ES6 #sec-array.prototype.fill */                                          \
   CPP(ArrayPrototypeFill)                                                      \
   /* ES6 #sec-array.from */                                                    \