Why would I std::move an std::shared_ptr?

I have been looking through the Clang source code and I found this snippet:

void CompilerInstance::setInvocation(
    std::shared_ptr<CompilerInvocation> Value) {
  Invocation = std::move(Value);
}

Why would I want to std::move an std::shared_ptr?

Is there any point transferring ownership on a shared resource?

Why wouldn't I just do this instead?

void CompilerInstance::setInvocation(
    std::shared_ptr<CompilerInvocation> Value) {
  Invocation = Value;
}