Adding V8_WARN_UNUSED_RESULT for specified TODOs

src/wasm/wasm-js.cc

Index: src/wasm/wasm-js.cc
diff --git a/src/wasm/wasm-js.cc b/src/wasm/wasm-js.cc
index 743a0e19da67aaae9ddb3801abbdcba2f12a6b75..0a81a528895a5118947ea2d0fb5c53a3c4379027 100644
--- a/src/wasm/wasm-js.cc
+++ b/src/wasm/wasm-js.cc
@@ -189,7 +189,8 @@ void WebAssemblyCompile(const v8::FunctionCallbackInfo<v8::Value>& args) {
 
   auto bytes = GetFirstArgumentAsBytes(args, &thrower);
   if (!IsCompilationAllowed(i_isolate, &thrower, args[0], true)) {
-    resolver->Reject(context, Utils::ToLocal(thrower.Reify()));
+    auto maybe = resolver->Reject(context, Utils::ToLocal(thrower.Reify()));
+    CHECK(!maybe.IsNothing());
     return;
   }
   DCHECK(!thrower.error());
@@ -337,7 +338,8 @@ void WebAssemblyInstantiate(const v8::FunctionCallbackInfo<v8::Value>& args) {
     thrower.TypeError(
         "Argument 0 must be provided and must be either a buffer source or a "
         "WebAssembly.Module object");
-    resolver->Reject(context, Utils::ToLocal(thrower.Reify()));
+    auto maybe = resolver->Reject(context, Utils::ToLocal(thrower.Reify()));
+    CHECK(!maybe.IsNothing());
     return;
   }
 
@@ -345,18 +347,21 @@ void WebAssemblyInstantiate(const v8::FunctionCallbackInfo<v8::Value>& args) {
   if (!first_arg->IsJSObject()) {
     thrower.TypeError(
         "Argument 0 must be a buffer source or a WebAssembly.Module object");
-    resolver->Reject(context, Utils::ToLocal(thrower.Reify()));
+    auto maybe = resolver->Reject(context, Utils::ToLocal(thrower.Reify()));
+    CHECK(!maybe.IsNothing());
     return;
   }
 
   auto maybe_imports = GetSecondArgumentAsImports(args, &thrower);
   if (thrower.error()) {
-    resolver->Reject(context, Utils::ToLocal(thrower.Reify()));
+    auto maybe = resolver->Reject(context, Utils::ToLocal(thrower.Reify()));
+    CHECK(!maybe.IsNothing());
     return;
   }
   if (!IsInstantiationAllowed(i_isolate, &thrower, args[0], maybe_imports,
                               true)) {
-    resolver->Reject(context, Utils::ToLocal(thrower.Reify()));
+    auto maybe = resolver->Reject(context, Utils::ToLocal(thrower.Reify()));
+    CHECK(!maybe.IsNothing());
     return;
   }
   i::Handle<i::JSPromise> promise = Utils::OpenHandle(*resolver->GetPromise());
@@ -369,7 +374,8 @@ void WebAssemblyInstantiate(const v8::FunctionCallbackInfo<v8::Value>& args) {
     // WebAssembly.instantiate(bytes, imports) -> {module, instance}
     auto bytes = GetFirstArgumentAsBytes(args, &thrower);
     if (thrower.error()) {
-      resolver->Reject(context, Utils::ToLocal(thrower.Reify()));
+      auto maybe = resolver->Reject(context, Utils::ToLocal(thrower.Reify()));
+      CHECK(!maybe.IsNothing());
       return;
     }
     i::wasm::AsyncCompileAndInstantiate(i_isolate, promise, bytes,