LibWeb/WebIDL: Store SimpleException message as a String{,View} variant

Author: https://github.com/linusg
Commit: 11b40dbcf5
Pull-request: https://github.com/SerenityOS/serenity/pull/17704
Reviewed-by: https://github.com/nico ✅

Userland/Libraries/LibWeb/Encoding/TextDecoder.cpp

@@ -14,9 +14,11 @@ namespace Web::Encoding {
 
 WebIDL::ExceptionOr<JS::NonnullGCPtr<TextDecoder>> TextDecoder::construct_impl(JS::Realm& realm, DeprecatedFlyString encoding)
 {
+    auto& vm = realm.vm();
+
     auto decoder = TextCodec::decoder_for(encoding);
     if (!decoder.has_value())
-        return WebIDL::SimpleException { WebIDL::SimpleExceptionType::TypeError, DeprecatedString::formatted("Invalid encoding {}", encoding) };
+        return WebIDL::SimpleException { WebIDL::SimpleExceptionType::TypeError, TRY_OR_THROW_OOM(vm, String::formatted("Invalid encoding {}", encoding)) };
 
     return MUST_OR_THROW_OOM(realm.heap().allocate<TextDecoder>(realm, realm, *decoder, move(encoding), false, false));
 }