Add GetProperty/GetElement to JSReceiver and use it where possible

test/cctest/compiler/test-run-jsobjects.cc

Index: test/cctest/compiler/test-run-jsobjects.cc
diff --git a/test/cctest/compiler/test-run-jsobjects.cc b/test/cctest/compiler/test-run-jsobjects.cc
index 4bf10ca8feb781758e1a8b9990c11ef35a3e77c6..80a918134fad00b3e7eacdf5c144de8e0cc09427 100644
--- a/test/cctest/compiler/test-run-jsobjects.cc
+++ b/test/cctest/compiler/test-run-jsobjects.cc
@@ -16,7 +16,7 @@ TEST(ArgumentsMapped) {
   CHECK(arguments->IsJSObject() && !arguments->IsJSArray());
   CHECK(JSObject::cast(*arguments)->HasSloppyArgumentsElements());
   Handle<String> l = T.isolate->factory()->length_string();
-  Handle<Object> length = JSObject::GetProperty(arguments, l).ToHandleChecked();
+  Handle<Object> length = Object::GetProperty(arguments, l).ToHandleChecked();
   CHECK_EQ(4, length->Number());
 }
 
@@ -29,7 +29,7 @@ TEST(ArgumentsUnmapped) {
   CHECK(arguments->IsJSObject() && !arguments->IsJSArray());
   CHECK(!JSObject::cast(*arguments)->HasSloppyArgumentsElements());
   Handle<String> l = T.isolate->factory()->length_string();
-  Handle<Object> length = JSObject::GetProperty(arguments, l).ToHandleChecked();
+  Handle<Object> length = Object::GetProperty(arguments, l).ToHandleChecked();
   CHECK_EQ(4, length->Number());
 }
 
@@ -42,7 +42,7 @@ TEST(ArgumentsRest) {
   CHECK(arguments->IsJSObject() && arguments->IsJSArray());
   CHECK(!JSObject::cast(*arguments)->HasSloppyArgumentsElements());
   Handle<String> l = T.isolate->factory()->length_string();
-  Handle<Object> length = JSObject::GetProperty(arguments, l).ToHandleChecked();
+  Handle<Object> length = Object::GetProperty(arguments, l).ToHandleChecked();
   CHECK_EQ(3, length->Number());
 }