Adding V8_WARN_UNUSED_RESULT for specified TODOs

src/wasm/wasm-module.cc

Index: src/wasm/wasm-module.cc
diff --git a/src/wasm/wasm-module.cc b/src/wasm/wasm-module.cc
index c592cdafcc2240a23555f2db891e8d37e8830ddc..acc751b2c02d38812a10d72fd5547bef18fffa62 100644
--- a/src/wasm/wasm-module.cc
+++ b/src/wasm/wasm-module.cc
@@ -2683,8 +2683,9 @@ void RejectPromise(Isolate* isolate, ErrorThrower* thrower,
   v8::Local<v8::Promise::Resolver> resolver =
       v8::Utils::PromiseToLocal(promise).As<v8::Promise::Resolver>();
   Handle<Context> context(isolate->context(), isolate);
-  resolver->Reject(v8::Utils::ToLocal(context),
+  auto maybe = resolver->Reject(v8::Utils::ToLocal(context),
                    v8::Utils::ToLocal(thrower->Reify()));
+  CHECK(!maybe.IsNothing());
 }
 
 void ResolvePromise(Isolate* isolate, Handle<JSPromise> promise,
@@ -2692,7 +2693,9 @@ void ResolvePromise(Isolate* isolate, Handle<JSPromise> promise,
   v8::Local<v8::Promise::Resolver> resolver =
       v8::Utils::PromiseToLocal(promise).As<v8::Promise::Resolver>();
   Handle<Context> context(isolate->context(), isolate);
-  resolver->Resolve(v8::Utils::ToLocal(context), v8::Utils::ToLocal(result));
+  auto maybe = resolver->Resolve(v8::Utils::ToLocal(context),
+                                 v8::Utils::ToLocal(result));
+  CHECK(!maybe.IsNothing());
 }
 
 }  // namespace