[debugging] Add %Verify() helper and check verify a HeapObject has a Map.

src/runtime/runtime-test.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/runtime/runtime-utils.h"
 
 #include <memory>
 
 #include "src/arguments.h"
 #include "src/compiler-dispatcher/optimizing-compile-dispatcher.h"
@@ skipping 810 matching lines @@
 }
 
 RUNTIME_FUNCTION(Runtime_ValidateWasmOrphanedInstance) {
   HandleScope shs(isolate);
   DCHECK_EQ(1, args.length());
   CONVERT_ARG_HANDLE_CHECKED_2(WasmInstanceObject, instance, 0);
   wasm::testing::ValidateOrphanedInstance(isolate, instance);
   return isolate->heap()->ToBoolean(true);
 }
 
+RUNTIME_FUNCTION(Runtime_Verify) {
+  HandleScope shs(isolate);
+  DCHECK_EQ(1, args.length());
+  CONVERT_ARG_HANDLE_CHECKED(Object, object, 0);
+#ifdef VERIFY_HEAP
+  object->ObjectVerify();
+#else
+  CHECK(object->IsObject());
+  if (object->IsHeapObject()) {
+    CHECK(HeapObject::cast(*object)->map()->IsMap());
+  } else {
+    CHECK(object->IsSmi());
+  }
+#endif
+  return isolate->heap()->ToBoolean(true);
+}
+
 }  // namespace internal
 }  // namespace v8