include fixing: api.h shouldn't include objects-inl.h

src/handles.h

Index: src/handles.h
diff --git a/src/handles.h b/src/handles.h
index 2c98209a1d5faf8047cda9e5be4a637a077057b4..831a301a5a75adc472e8f3578d1cf4bdc51d0b01 100644
--- a/src/handles.h
+++ b/src/handles.h
@@ -91,11 +91,10 @@ class Handle final : public HandleBase {
  public:
   V8_INLINE explicit Handle(T** location = nullptr)
       : HandleBase(reinterpret_cast<Object**>(location)) {
-    Object* a = nullptr;
-    T* b = nullptr;
-    a = b;  // Fake assignment to enforce type checks.
-    USE(a);
+    // Type check:
+    DCHECK(T::IsObjectSubclass());

[Michael Starzinger, 2017/01/09 11:33:07]

Are we allowed to use std::is_base_of (https://chromium-cpp.appspot.com/ says
everything in <type_traits> is allowed)? I have the feeling this could be
expressed as a static assert in that case. WDYT? I am thinking along the lines
of ...

static_assert(std::is_base_of<Object, T>::value, "static type violation");

[marja, 2017/01/09 11:48:36]

Done.

   }
+
   V8_INLINE explicit Handle(T* object) : Handle(object, object->GetIsolate()) {}
   V8_INLINE Handle(T* object, Isolate* isolate) : HandleBase(object, isolate) {}