message: Implicitly initialize platforms in PlatformUtil::GetSupportedPlatforms.
diff: @@ -70,6 +70,9 @@ PlatformUtil::GetSupportedPlatforms() {
  for (se::Platform* platform : all_platforms) {
  auto compiler_status = Compiler::GetForPlatform(platform);
  if (compiler_status.ok()) {
  + if (!platform->Initialized()) {
  + TF_RETURN_IF_ERROR(platform->Initialize({}));
  + }
  platforms.push_back(platform);
  } else {
  LOG(INFO) << "platform " << platform->Name() << " present but no "
  