Add unittests to keep InstanceType lists in sync

STRUCT_LIST and INSTANCE_TYPE_LIST are now forced to have the same order
as the InstanceType enum.

Drive-by-fix 1: Move type check and cast functions closer together in objects-inl.h

Drive-by-fix 2: Remove unused instance types SIGNATURE_INFO_TYPE and  TYPE_SWITCH_INFO_TYPE.

BUG=

Review-Url: https://codereview.chromium.org/2578573002
Cr-Commit-Position: refs/heads/master@{#41804}

include/v8.h

@@ -8380,8 +8380,8 @@ class Internals {
   static const int kNodeIsIndependentShift = 3;
   static const int kNodeIsActiveShift = 4;
 
-  static const int kJSObjectType = 0xbe;
-  static const int kJSApiObjectType = 0xbd;
+  static const int kJSApiObjectType = 0xbb;
+  static const int kJSObjectType = 0xbc;
   static const int kFirstNonstringType = 0x80;
   static const int kOddballType = 0x83;
   static const int kForeignType = 0x87;

src/ast/ast-types.cc

@@ -303,8 +303,6 @@ AstType::bitset AstBitsetType::Lub(i::Map* map) {
     case PROMISE_REACTION_JOB_INFO_TYPE:
     case FUNCTION_TEMPLATE_INFO_TYPE:
     case OBJECT_TEMPLATE_INFO_TYPE:
-    case SIGNATURE_INFO_TYPE:
-    case TYPE_SWITCH_INFO_TYPE:
     case ALLOCATION_MEMENTO_TYPE:
     case TYPE_FEEDBACK_INFO_TYPE:
     case ALIASED_ARGUMENTS_ENTRY_TYPE:

src/compiler/types.cc

@@ -310,8 +310,6 @@ Type::bitset BitsetType::Lub(i::Map* map) {
     case INTERCEPTOR_INFO_TYPE:
     case CALL_HANDLER_INFO_TYPE:
     case OBJECT_TEMPLATE_INFO_TYPE:
-    case SIGNATURE_INFO_TYPE:
-    case TYPE_SWITCH_INFO_TYPE:
     case ALLOCATION_MEMENTO_TYPE:
     case TYPE_FEEDBACK_INFO_TYPE:
     case ALIASED_ARGUMENTS_ENTRY_TYPE:

test/unittests/BUILD.gn

@@ -120,6 +120,7 @@ v8_executable("unittests") {
     "libplatform/task-queue-unittest.cc",
     "libplatform/worker-thread-unittest.cc",
     "locked-queue-unittest.cc",
+    "object-unittest.cc",
     "register-configuration-unittest.cc",
     "run-all-unittests.cc",
     "source-position-table-unittest.cc",

test/unittests/heap/heap-unittest.cc

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #include <cmath>
+#include <iostream>
 #include <limits>
 
 #include "src/objects.h"

test/unittests/object-unittest.cc

+// Copyright 2016 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 <cmath>
+#include <iostream>
+#include <limits>
+
+#include "src/objects-inl.h"
+#include "src/objects.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace v8 {
+namespace internal {
+
+TEST(Object, InstanceTypeListOrder) {
+  int current = 0;
+  int last = -1;
+  InstanceType current_type = static_cast<InstanceType>(current);
+  EXPECT_EQ(current_type, InstanceType::FIRST_TYPE);
+  EXPECT_EQ(current_type, InstanceType::INTERNALIZED_STRING_TYPE);
+#define TEST_INSTANCE_TYPE(type)                                           \
+  current_type = InstanceType::type;                                       \
+  current = static_cast<int>(current_type);                                \
+  if (current > static_cast<int>(LAST_NAME_TYPE)) {                        \
+    EXPECT_EQ(last + 1, current);                                          \
+  }                                                                        \
+  EXPECT_LT(last, current) << " INSTANCE_TYPE_LIST is not ordered: "       \
+                           << "last = " << static_cast<InstanceType>(last) \
+                           << " vs. current = " << current_type;           \
+  last = current;
+
+  INSTANCE_TYPE_LIST(TEST_INSTANCE_TYPE)
+#undef TEST_INSTANCE_TYPE
+}
+
+TEST(Object, StructListOrder) {
+  int current = static_cast<int>(InstanceType::ACCESSOR_INFO_TYPE);
+  int last = current - 1;
+  ASSERT_LT(0, last);
+  InstanceType current_type = static_cast<InstanceType>(current);
+#define TEST_STRUCT(type, class, name)                 \
+  current_type = InstanceType::type##_TYPE;            \
+  current = static_cast<int>(current_type);            \
+  EXPECT_EQ(last + 1, current)                         \
+      << " STRUCT_LIST is not ordered: "               \
+      << " last = " << static_cast<InstanceType>(last) \
+      << " vs. current = " << current_type;            \
+  last = current;
+
+  STRUCT_LIST(TEST_STRUCT)
+#undef TEST_STRUCT
+}
+
+}  // namespace internal
+}  // namespace v8

test/unittests/unittests.gyp

@@ -118,6 +118,7 @@
       'heap/scavenge-job-unittest.cc',
       'heap/slot-set-unittest.cc',
       'locked-queue-unittest.cc',
+      'object-unittest.cc',
       'register-configuration-unittest.cc',
       'run-all-unittests.cc',
       'source-position-table-unittest.cc',