The AudioFormatManager also takes an InputStream as well: AudioFormatManager::createReaderFor (InputStream* audioFileStream), and the memory can be turned into a MemoryInputStream.
IIRC:
MemoryInputStream* input = new MemoryInputStream (BinaryData::fille_wav, BinaryData::file_wav_size, false);
auto reader = audioFormatManager.createReaderFor (input);
HTH
EDIT: Fixed code after @jules reply…