[msvc] fix build errors (#4451)

MSVC doesn't consider atomic<u64> to be trivially copyable on x86 (why?).
And other chary idiosyncrasies from constructing `std::optional<uint8_t>`

Signed-off-by: lizzie <lizzie@eden-emu.dev>

- [x] I have read and followed the [Contribution Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/CONTRIBUTING.md#code-contributions).
- [x] I have read and followed the [AI Policy](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/AI.md)
- [x] I have read and followed the [Coding Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/Coding.md) to the best of my ability.

-------------------

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4451
Reviewed-by: Maufeat <sahyno1996@gmail.com>
Reviewed-by: CamilleLaVey <camillelavey99@gmail.com>

src/core/hle/service/ssl/ssl.cpp

@@ -238,7 +238,7 @@ private:
 
     Result GetSocketDescriptor(Out<u32> out_fd) {
         LOG_WARNING(Service_SSL, "(STUBBED)");
-        *out_fd = socket->GetFD();
+        *out_fd = uint32_t(socket->GetFD());
         R_SUCCEED();
     }