Use unaligned mplace, test passed

Author: tiif

src/shims/unix/linux/eventfd.rs

@@ -68,7 +68,7 @@ impl FileDescription for Event {
         ecx: &mut MiriInterpCx<'tcx>,
     ) -> InterpResult<'tcx> {
         // eventfd read at the size of u64.
-        let buf_place = ecx.ptr_to_mplace(ptr, ecx.machine.layouts.u64);
+        let buf_place = ecx.ptr_to_mplace_unaligned(ptr, ecx.machine.layouts.u64);
         // Check the size of slice, and return error only if the size of the slice < 8.
         if len < U64_ARRAY_SIZE.try_into().unwrap() {
             let result = Err(Error::from(ErrorKind::InvalidInput));