[turbofan] Add unit tests for ReduceJSCreateArguments.

test/unittests/compiler/js-typed-lowering-unittest.cc

Index: test/unittests/compiler/js-typed-lowering-unittest.cc
diff --git a/test/unittests/compiler/js-typed-lowering-unittest.cc b/test/unittests/compiler/js-typed-lowering-unittest.cc
index 2015c7edf033181fedf3ef537915eeea32f06f6a..30b6a3b8eeb1ee80564a13788fb35bc212ce9e7c 100644
--- a/test/unittests/compiler/js-typed-lowering-unittest.cc
+++ b/test/unittests/compiler/js-typed-lowering-unittest.cc
@@ -89,6 +89,18 @@ class JSTypedLoweringTest : public TypedGraphTest {
     return reducer.Reduce(node);
   }
 
+  Node* FrameState(Handle<SharedFunctionInfo> shared, Node* outer_frame_state) {
+    Node* state_values = graph()->NewNode(common()->StateValues(0));
+    return graph()->NewNode(
+        common()->FrameState(BailoutId::None(),
+                             OutputFrameStateCombine::Ignore(),
+                             common()->CreateFrameStateFunctionInfo(
+                                 FrameStateType::kJavaScriptFunction, 1, 0,
+                                 shared, CALL_MAINTAINS_NATIVE_CONTEXT)),
+        state_values, state_values, state_values, NumberConstant(0),
+        UndefinedConstant(), outer_frame_state);
+  }
+
   Handle<JSArrayBuffer> NewArrayBuffer(void* bytes, size_t byte_length) {
     Handle<JSArrayBuffer> buffer = factory()->NewJSArrayBuffer();
     JSArrayBuffer::Setup(buffer, isolate(), true, bytes, byte_length);
@@ -985,6 +997,72 @@ TEST_F(JSTypedLoweringTest, JSAddWithString) {
 
 
 // -----------------------------------------------------------------------------
+// JSCreateArguments
+
+
+TEST_F(JSTypedLoweringTest, JSCreateArgumentsViaStub) {
+  Node* const closure = Parameter(Type::Any());
+  Node* const context = UndefinedConstant();
+  Node* const effect = graph()->start();
+  Node* const control = graph()->start();
+  Handle<SharedFunctionInfo> shared(isolate()->object_function()->shared());
+  Node* const frame_state = FrameState(shared, graph()->start());
+  Reduction r = Reduce(
+      graph()->NewNode(javascript()->CreateArguments(
+                           CreateArgumentsParameters::kMappedArguments, 0),
+                       closure, context, frame_state, effect, control));
+  ASSERT_TRUE(r.Changed());
+  EXPECT_THAT(r.replacement(),
+              IsCall(_, IsHeapConstant(CodeFactory::ArgumentsAccess(
+                                           isolate(), false, false)
+                                           .code()),
+                     closure, IsNumberConstant(0), _, effect, control));
+}
+
+
+TEST_F(JSTypedLoweringTest, JSCreateArgumentsInlinedMapped) {
+  Node* const closure = Parameter(Type::Any());
+  Node* const context = UndefinedConstant();
+  Node* const effect = graph()->start();
+  Node* const control = graph()->start();
+  Handle<SharedFunctionInfo> shared(isolate()->object_function()->shared());
+  Node* const frame_state_outer = FrameState(shared, graph()->start());
+  Node* const frame_state_inner = FrameState(shared, frame_state_outer);
+  Reduction r = Reduce(
+      graph()->NewNode(javascript()->CreateArguments(
+                           CreateArgumentsParameters::kMappedArguments, 0),
+                       closure, context, frame_state_inner, effect, control));
+  ASSERT_TRUE(r.Changed());
+  EXPECT_THAT(r.replacement(),
+              IsFinishRegion(
+                  IsAllocate(IsNumberConstant(Heap::kSloppyArgumentsObjectSize),
+                             IsBeginRegion(effect), control),
+                  _));
+}
+
+
+TEST_F(JSTypedLoweringTest, JSCreateArgumentsInlinedUnmapped) {
+  Node* const closure = Parameter(Type::Any());
+  Node* const context = UndefinedConstant();
+  Node* const effect = graph()->start();
+  Node* const control = graph()->start();
+  Handle<SharedFunctionInfo> shared(isolate()->object_function()->shared());
+  Node* const frame_state_outer = FrameState(shared, graph()->start());
+  Node* const frame_state_inner = FrameState(shared, frame_state_outer);
+  Reduction r = Reduce(
+      graph()->NewNode(javascript()->CreateArguments(
+                           CreateArgumentsParameters::kUnmappedArguments, 0),
+                       closure, context, frame_state_inner, effect, control));
+  ASSERT_TRUE(r.Changed());
+  EXPECT_THAT(r.replacement(),
+              IsFinishRegion(
+                  IsAllocate(IsNumberConstant(Heap::kStrictArgumentsObjectSize),
+                             IsBeginRegion(effect), control),
+                  _));
+}
+
+
+// -----------------------------------------------------------------------------
 // JSCreateClosure