[Base] Check success of sync primitive creation

- Mainly use `assert`s, since failure is very rare
- Forward failure of `CreateSemaphore` to guests because it is more easy
  to trigger with invalid initial parameters.

src/xenia/gpu/command_processor.cc

@@ -41,7 +41,9 @@ CommandProcessor::CommandProcessor(GraphicsSystem* graphics_system,
       trace_writer_(graphics_system->memory()->physical_membase()),
       worker_running_(true),
       write_ptr_index_event_(xe::threading::Event::CreateAutoResetEvent(false)),
-      write_ptr_index_(0) {}
+      write_ptr_index_(0) {
+  assert_not_null(write_ptr_index_event_);
+}
 
 CommandProcessor::~CommandProcessor() = default;