[wasm] Differentiate unnamed and empty names

src/runtime/runtime-function.cc

Index: src/runtime/runtime-function.cc
diff --git a/src/runtime/runtime-function.cc b/src/runtime/runtime-function.cc
index 7d7b81109284cc88a597d2f05214076fe26aca17..eb5cf9311d7c213c11f51c0cb5097ed82ec3bdd6 100644
--- a/src/runtime/runtime-function.cc
+++ b/src/runtime/runtime-function.cc
@@ -307,10 +307,15 @@ RUNTIME_FUNCTION(Runtime_WasmGetFunctionName) {
   HandleScope scope(isolate);
   DCHECK_EQ(2, args.length());
 
-  CONVERT_ARG_HANDLE_CHECKED(JSObject, wasm, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Object, wasm, 0);
   CONVERT_SMI_ARG_CHECKED(func_index, 1);
 
-  return *wasm::GetWasmFunctionName(wasm, func_index);
+  RUNTIME_ASSERT(wasm->IsUndefined() || wasm->IsJSObject());
+  Handle<Object> funName =
+      wasm->IsUndefined()
+          ? wasm
+          : wasm::GetWasmFunctionName(Handle<JSObject>::cast(wasm), func_index);
+  return *funName;
 }
 
 }  // namespace internal