rust: bindings: add Send and Sync markers for types that have bindings

This is needed for the MemoryRegionOps<T> to be declared as static;
Rust requires static elements to be Sync.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

rust/qemu-api/src/irq.rs

@@ -43,6 +43,9 @@ where
     _marker: PhantomData<T>,
 }
 
+// SAFETY: the implementation asserts via `BqlCell` that the BQL is taken
+unsafe impl<T> Sync for InterruptSource<T> where c_int: From<T> {}
+
 impl InterruptSource<bool> {
     /// Send a low (`false`) value to the interrupt sink.
     pub fn lower(&self) {